Measurement of sounding reference signal reflections off of reconfigurable intelligent surfaces

ABSTRACT

Disclosed are techniques for communication. In an aspect, a wireless node (e.g., UE or BS) measures a first TOA of a first SRS-P from a UE, a second TOA of a reflection of a second SRS-P from the UE off of a first RIS, and a third TOA of a reflection of a third SRS-P from the UE off of a second RIS. The UE transmits, to a position estimation entity, measurement information based on the first, second and third TOAs. The position estimation entity determines a positioning estimate of the UE based at least in part on the measurement information.

CROSS-REFERENCE TO RELATED APPLICATION

The present application for patent is a national stage application,filed under 35 U.S.C. § 371, claiming priority of International PatentApplication No. PCT/CN2021/078831, entitled “MEASUREMENT OF SOUNDINGREFERENCE SIGNAL REFLECTIONS OFF OF RECONFIGURABLE INTELLIGENTSURFACES,” filed Mar. 3, 2021, assigned to the assignee hereof, andexpressly incorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

Aspects of the disclosure relate generally to wireless communications.

2. Description of the Related Art

Wireless communication systems have developed through variousgenerations, including a first-generation analog wireless phone service(1G), a second-generation (2G) digital wireless phone service (includinginterim 2.5G and 2.75G networks), a third-generation (3G) high speeddata, Internet-capable wireless service and a fourth-generation (4G)service (e.g., Long Term Evolution (LTE) or WiMax). There are presentlymany different types of wireless communication systems in use, includingcellular and personal communications service (PCS) systems. Examples ofknown cellular systems include the cellular analog advanced mobile phonesystem (AMPS), and digital cellular systems based on code divisionmultiple access (CDMA), frequency division multiple access (FDMA), timedivision multiple access (TDMA), the Global System for Mobilecommunications (GSM), etc.

A fifth generation (5G) wireless standard, referred to as New Radio(NR), calls for higher data transfer speeds, greater numbers ofconnections, and better coverage, among other improvements. The 5Gstandard, according to the Next Generation Mobile Networks Alliance, isdesigned to provide data rates of several tens of megabits per second toeach of tens of thousands of users, with 1 gigabit per second to tens ofworkers on an office floor. Several hundreds of thousands ofsimultaneous connections should be supported in order to support largesensor deployments. Consequently, the spectral efficiency of 5G mobilecommunications should be significantly enhanced compared to the current4G standard. Furthermore, signaling efficiencies should be enhanced andlatency should be substantially reduced compared to current standards.

SUMMARY

The following presents a simplified summary relating to one or moreaspects disclosed herein. Thus, the following summary should not beconsidered an extensive overview relating to all contemplated aspects,nor should the following summary be considered to identify key orcritical elements relating to all contemplated aspects or to delineatethe scope associated with any particular aspect. Accordingly, thefollowing summary has the sole purpose to present certain conceptsrelating to one or more aspects relating to the mechanisms disclosedherein in a simplified form to precede the detailed descriptionpresented below.

In an aspect, a method of operating a wireless node includes measuring afirst time of arrival (TOA) of a first sounding reference signal forpositioning (SRS-P) from a user equipment (UE); measuring a second TOAof a reflection of a second SRS-P from the UE off of a firstreconfigurable intelligent surface (RIS); measuring a third TOA of areflection of a third SRS-P from the UE off of a second RIS; andtransmitting, to a position estimation entity, measurement informationbased on the first, second and third TOAs.

In an aspect, a method of operating a position estimation entityincludes receiving, from a wireless node, measurement information basedon a first time of arrival (TOA) of a first sounding reference signalfor positioning (SRS-P) from a user equipment (UE), a second TOA of areflection of a second SRS-P from the UE off of a first reconfigurableintelligent surface (RIS), and a third TOA of a reflection of a thirdSRS-P from the UE off of a second RIS; and determining a positioningestimate of the UE based at least in part on the measurementinformation.

In an aspect, a wireless node includes a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: measure a first time of arrival (TOA) of a first soundingreference signal for positioning (SRS-P) from a user equipment (UE);measure a second TOA of a reflection of a second SRS-P from the UE offof a first reconfigurable intelligent surface (RIS); measure a third TOAof a reflection of a third SRS-P from the UE off of a second RIS; andtransmit, to a position estimation entity, measurement information basedon the first, second and third TOAs.

In an aspect, a position estimation entity includes a memory; at leastone transceiver; and at least one processor communicatively coupled tothe memory and the at least one transceiver, the at least one processorconfigured to: receive, from a wireless node, measurement informationbased on a first time of arrival (TOA) of a first sounding referencesignal for positioning (SRS-P) from a user equipment (UE), a second TOAof a reflection of a second SRS-P from the UE off of a firstreconfigurable intelligent surface (RIS), and a third TOA of areflection of a third SRS-P from the UE off of a second RIS; anddetermine a positioning estimate of the UE based at least in part on themeasurement information.

Other objects and advantages associated with the aspects disclosedherein will be apparent to those skilled in the art based on theaccompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description ofvarious aspects of the disclosure and are provided solely forillustration of the aspects and not limitation thereof.

FIG. 1 illustrates an example wireless communications system, accordingto aspects of the disclosure.

FIGS. 2A and 2B illustrate example wireless network structures,according to aspects of the disclosure.

FIGS. 3A to 3C are simplified block diagrams of several sample aspectsof components that may be employed in a user equipment (UE), a basestation, and a network entity, respectively, and configured to supportcommunications as taught herein.

FIGS. 4A to 4D are diagrams illustrating example frame structures andchannels within the frame structures, according to aspects of thedisclosure.

FIG. 5 illustrates an exemplary wireless communications system 600according to aspects of the disclosure.

FIG. 6 illustrates an example system for wireless communication using areconfigurable intelligent surface (RIS), according to aspects of thedisclosure.

FIG. 7 is a diagram of an example architecture of a RIS, according toaspects of the disclosure.

FIG. 8 illustrates an exemplary process of communications according toan aspect of the disclosure.

FIG. 9 illustrates an exemplary process of communications according toanother aspect of the disclosure.

FIG. 10 illustrates an example implementation of the processes of FIGS.8-9 in accordance with an aspect of the disclosure.

FIG. 11 illustrates an example implementation of the processes of FIGS.8-9 in accordance with another aspect of the disclosure.

DETAILED DESCRIPTION

Aspects of the disclosure are provided in the following description andrelated drawings directed to various examples provided for illustrationpurposes. Alternate aspects may be devised without departing from thescope of the disclosure. Additionally, well-known elements of thedisclosure will not be described in detail or will be omitted so as notto obscure the relevant details of the disclosure.

The words “exemplary” and/or “example” are used herein to mean “servingas an example, instance, or illustration.” Any aspect described hereinas “exemplary” and/or “example” is not necessarily to be construed aspreferred or advantageous over other aspects. Likewise, the term“aspects of the disclosure” does not require that all aspects of thedisclosure include the discussed feature, advantage or mode ofoperation.

Those of skill in the art will appreciate that the information andsignals described below may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the description below may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof, depending inpart on the particular application, in part on the desired design, inpart on the corresponding technology, etc.

Further, many aspects are described in terms of sequences of actions tobe performed by, for example, elements of a computing device. It will berecognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, the sequence(s)of actions described herein can be considered to be embodied entirelywithin any form of non-transitory computer-readable storage mediumhaving stored therein a corresponding set of computer instructions that,upon execution, would cause or instruct an associated processor of adevice to perform the functionality described herein. Thus, the variousaspects of the disclosure may be embodied in a number of differentforms, all of which have been contemplated to be within the scope of theclaimed subject matter. In addition, for each of the aspects describedherein, the corresponding form of any such aspects may be describedherein as, for example, “logic configured to” perform the describedaction.

As used herein, the terms “user equipment” (UE) and “base station” arenot intended to be specific or otherwise limited to any particular radioaccess technology (RAT), unless otherwise noted. In general, a UE may beany wireless communication device (e.g., a mobile phone, router, tabletcomputer, laptop computer, consumer asset tracking device, wearable(e.g., smartwatch, glasses, augmented reality (AR)/virtual reality (VR)headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.),Internet of Things (IoT) device, etc.) used by a user to communicateover a wireless communications network. A UE may be mobile or may (e.g.,at certain times) be stationary, and may communicate with a radio accessnetwork (RAN). As used herein, the term “UE” may be referred tointerchangeably as an “access terminal” or “AT,” a “client device,” a“wireless device,” a “subscriber device,” a “subscriber terminal,” a“subscriber station,” a “user terminal” or “UT,” a “mobile device,” a“mobile terminal,” a “mobile station,” or variations thereof. Generally,UEs can communicate with a core network via a RAN, and through the corenetwork the UEs can be connected with external networks such as theInternet and with other UEs. Of course, other mechanisms of connectingto the core network and/or the Internet are also possible for the UEs,such as over wired access networks, wireless local area network (WLAN)networks (e.g., based on the Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 specification, etc.) and so on.

A base station may operate according to one of several RATs incommunication with UEs depending on the network in which it is deployed,and may be alternatively referred to as an access point (AP), a networknode, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), aNew Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A basestation may be used primarily to support wireless access by UEs,including supporting data, voice, and/or signaling connections for thesupported UEs. In some systems a base station may provide purely edgenode signaling functions while in other systems it may provideadditional control and/or network management functions. A communicationlink through which UEs can send signals to a base station is called anuplink (UL) channel (e.g., a reverse traffic channel, a reverse controlchannel, an access channel, etc.). A communication link through whichthe base station can send signals to UEs is called a downlink (DL) orforward link channel (e.g., a paging channel, a control channel, abroadcast channel, a forward traffic channel, etc.). As used herein theterm traffic channel (TCH) can refer to either an uplink/reverse ordownlink/forward traffic channel.

The term “base station” may refer to a single physicaltransmission-reception point (TRP) or to multiple physical TRPs that mayor may not be co-located. For example, where the term “base station”refers to a single physical TRP, the physical TRP may be an antenna ofthe base station corresponding to a cell (or several cell sectors) ofthe base station. Where the term “base station” refers to multipleco-located physical TRPs, the physical TRPs may be an array of antennas(e.g., as in a multiple-input multiple-output (MIMO) system or where thebase station employs beamforming) of the base station. Where the term“base station” refers to multiple non-co-located physical TRPs, thephysical TRPs may be a distributed antenna system (DAS) (a network ofspatially separated antennas connected to a common source via atransport medium) or a remote radio head (RRH) (a remote base stationconnected to a serving base station). Alternatively, the non-co-locatedphysical TRPs may be the serving base station receiving the measurementreport from the UE and a neighbor base station whose reference radiofrequency (RF) signals the UE is measuring. Because a TRP is the pointfrom which a base station transmits and receives wireless signals, asused herein, references to transmission from or reception at a basestation are to be understood as referring to a particular TRP of thebase station.

In some implementations that support positioning of UEs, a base stationmay not support wireless access by UEs (e.g., may not support data,voice, and/or signaling connections for UEs), but may instead transmitreference signals to UEs to be measured by the UEs, and/or may receiveand measure signals transmitted by the UEs. Such a base station may bereferred to as a positioning beacon (e.g., when transmitting signals toUEs) and/or as a location measurement unit (e.g., when receiving andmeasuring signals from UEs).

An “RF signal” comprises an electromagnetic wave of a given frequencythat transports information through the space between a transmitter anda receiver. As used herein, a transmitter may transmit a single “RFsignal” or multiple “RF signals” to a receiver. However, the receivermay receive multiple “RF signals” corresponding to each transmitted RFsignal due to the propagation characteristics of RF signals throughmultipath channels. The same transmitted RF signal on different pathsbetween the transmitter and receiver may be referred to as a “multipath”RF signal.

FIG. 1 illustrates an example wireless communications system 100,according to aspects of the disclosure. The wireless communicationssystem 100 (which may also be referred to as a wireless wide areanetwork (WWAN)) may include various base stations 102 (labeled “BS”) andvarious UEs 104. The base stations 102 may include macro cell basestations (high power cellular base stations) and/or small cell basestations (low power cellular base stations). In an aspect, the macrocell base station may include eNBs and/or ng-eNBs where the wirelesscommunications system 100 corresponds to an LTE network, or gNBs wherethe wireless communications system 100 corresponds to a NR network, or acombination of both, and the small cell base stations may includefemtocells, picocells, microcells, etc.

The base stations 102 may collectively form a RAN and interface with acore network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC))through backhaul links 122, and through the core network 170 to one ormore location servers 172 (e.g., a location management function (LMF) ora secure user plane location (SUPL) location platform (SLP)). Thelocation server(s) 172 may be part of core network 170 or may beexternal to core network 170. In addition to other functions, the basestations 102 may perform functions that relate to one or more oftransferring user data, radio channel ciphering and deciphering,integrity protection, header compression, mobility control functions(e.g., handover, dual connectivity), inter-cell interferencecoordination, connection setup and release, load balancing, distributionfor non-access stratum (NAS) messages, NAS node selection,synchronization, RAN sharing, multimedia broadcast multicast service(MBMS), subscriber and equipment trace, RAN information management(RIM), paging, positioning, and delivery of warning messages. The basestations 102 may communicate with each other directly or indirectly(e.g., through the EPC/5GC) over backhaul links 134, which may be wiredor wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. In an aspect, one or more cellsmay be supported by a base station 102 in each geographic coverage area110. A “cell” is a logical communication entity used for communicationwith a base station (e.g., over some frequency resource, referred to asa carrier frequency, component carrier, carrier, band, or the like), andmay be associated with an identifier (e.g., a physical cell identifier(PCI), a virtual cell identifier (VCI), a cell global identifier (CGI))for distinguishing cells operating via the same or a different carrierfrequency. In some cases, different cells may be configured according todifferent protocol types (e.g., machine-type communication (MTC),narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others)that may provide access for different types of UEs. Because a cell issupported by a specific base station, the term “cell” may refer toeither or both of the logical communication entity and the base stationthat supports it, depending on the context. In some cases, the term“cell” may also refer to a geographic coverage area of a base station(e.g., a sector), insofar as a carrier frequency can be detected andused for communication within some portion of geographic coverage areas110.

While neighboring macro cell base station 102 geographic coverage areas110 may partially overlap (e.g., in a handover region), some of thegeographic coverage areas 110 may be substantially overlapped by alarger geographic coverage area 110. For example, a small cell (SC) basestation 102′ may have a geographic coverage area 110′ that substantiallyoverlaps with the geographic coverage area 110 of one or more macro cellbase stations 102. A network that includes both small cell and macrocell base stations may be known as a heterogeneous network. Aheterogeneous network may also include home eNBs (HeNBs), which mayprovide service to a restricted group known as a closed subscriber group(CSG).

The communication links 120 between the base stations 102 and the UEs104 may include uplink (also referred to as reverse link) transmissionsfrom a UE 104 to a base station 102 and/or downlink (also referred to asforward link) transmissions from a base station 102 to a UE 104. Thecommunication links 120 may use MIMO antenna technology, includingspatial multiplexing, beamforming, and/or transmit diversity. Thecommunication links 120 may be through one or more carrier frequencies.Allocation of carriers may be asymmetric with respect to downlink anduplink (e.g., more or less carriers may be allocated for downlink thanfor uplink).

The wireless communications system 100 may further include a wirelesslocal area network (WLAN) access point (AP) 150 in communication withWLAN stations (STAs) 152 via communication links 154 in an unlicensedfrequency spectrum (e.g., 5 GHz). When communicating in an unlicensedfrequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may performa clear channel assessment (CCA) or listen before talk (LBT) procedureprior to communicating in order to determine whether the channel isavailable.

The small cell base station 102′ may operate in a licensed and/or anunlicensed frequency spectrum. When operating in an unlicensed frequencyspectrum, the small cell base station 102′ may employ LTE or NRtechnology and use the same 5 GHz unlicensed frequency spectrum as usedby the WLAN AP 150. The small cell base station 102′, employing LTE/5Gin an unlicensed frequency spectrum, may boost coverage to and/orincrease capacity of the access network. NR in unlicensed spectrum maybe referred to as NR-U. LTE in an unlicensed spectrum may be referred toas LTE-U, licensed assisted access (LAA), or MulteFire.

The wireless communications system 100 may further include a millimeterwave (mmW) base station 180 that may operate in mmW frequencies and/ornear mmW frequencies in communication with a UE 182. Extremely highfrequency (EHF) is part of the RF in the electromagnetic spectrum. EHFhas a range of 30 GHz to 300 GHz and a wavelength between 1 millimeterand 10 millimeters. Radio waves in this band may be referred to as amillimeter wave. Near mmW may extend down to a frequency of 3 GHz with awavelength of 100 millimeters. The super high frequency (SHF) bandextends between 3 GHz and 30 GHz, also referred to as centimeter wave.Communications using the mmW/near mmW radio frequency band have highpath loss and a relatively short range. The mmW base station 180 and theUE 182 may utilize beamforming (transmit and/or receive) over a mmWcommunication link 184 to compensate for the extremely high path lossand short range. Further, it will be appreciated that in alternativeconfigurations, one or more base stations 102 may also transmit usingmmW or near mmW and beamforming. Accordingly, it will be appreciatedthat the foregoing illustrations are merely examples and should not beconstrued to limit the various aspects disclosed herein.

Transmit beamforming is a technique for focusing an RF signal in aspecific direction. Traditionally, when a network node (e.g., a basestation) broadcasts an RF signal, it broadcasts the signal in alldirections (omni-directionally). With transmit beamforming, the networknode determines where a given target device (e.g., a UE) is located(relative to the transmitting network node) and projects a strongerdownlink RF signal in that specific direction, thereby providing afaster (in terms of data rate) and stronger RF signal for the receivingdevice(s). To change the directionality of the RF signal whentransmitting, a network node can control the phase and relativeamplitude of the RF signal at each of the one or more transmitters thatare broadcasting the RF signal. For example, a network node may use anarray of antennas (referred to as a “phased array” or an “antennaarray”) that creates a beam of RF waves that can be “steered” to pointin different directions, without actually moving the antennas.Specifically, the RF current from the transmitter is fed to theindividual antennas with the correct phase relationship so that theradio waves from the separate antennas add together to increase theradiation in a desired direction, while cancelling to suppress radiationin undesired directions.

Transmit beams may be quasi-co-located, meaning that they appear to thereceiver (e.g., a UE) as having the same parameters, regardless ofwhether or not the transmitting antennas of the network node themselvesare physically co-located. In NR, there are four types ofquasi-co-location (QCL) relations. Specifically, a QCL relation of agiven type means that certain parameters about a target reference RFsignal on a target beam can be derived from information about a sourcereference RF signal on a source beam. If the source reference RF signalis QCL Type A, the receiver can use the source reference RF signal toestimate the Doppler shift, Doppler spread, average delay, and delayspread of a target reference RF signal transmitted on the same channel.If the source reference RF signal is QCL Type B, the receiver can usethe source reference RF signal to estimate the Doppler shift and Dopplerspread of a target reference RF signal transmitted on the same channel.If the source reference RF signal is QCL Type C, the receiver can usethe source reference RF signal to estimate the Doppler shift and averagedelay of a target reference RF signal transmitted on the same channel.If the source reference RF signal is QCL Type D, the receiver can usethe source reference RF signal to estimate the spatial receive parameterof a target reference RF signal transmitted on the same channel.

In receive beamforming, the receiver uses a receive beam to amplify RFsignals detected on a given channel. For example, the receiver canincrease the gain setting and/or adjust the phase setting of an array ofantennas in a particular direction to amplify (e.g., to increase thegain level of) the RF signals received from that direction. Thus, when areceiver is said to beamform in a certain direction, it means the beamgain in that direction is high relative to the beam gain along otherdirections, or the beam gain in that direction is the highest comparedto the beam gain in that direction of all other receive beams availableto the receiver. This results in a stronger received signal strength(e.g., reference signal received power (RSRP), reference signal receivedquality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) ofthe RF signals received from that direction.

Receive beams may be spatially related. A spatial relation means thatparameters for a transmit beam for a second reference signal can bederived from information about a receive beam for a first referencesignal. For example, a UE may use a particular receive beam to receiveone or more reference downlink reference signals (e.g., positioningreference signals (PRS), tracking reference signals (TRS), phasetracking reference signal (PTRS), cell-specific reference signals (CRS),channel state information reference signals (CSI-RS), primarysynchronization signals (PSS), secondary synchronization signals (SSS),synchronization signal blocks (SSBs), etc.) from a base station. The UEcan then form a transmit beam for sending one or more uplink referencesignals (e.g., uplink positioning reference signals (UL-PRS), soundingreference signal (SRS), demodulation reference signals (DMRS), PTRS,etc.) to that base station based on the parameters of the receive beam.

Note that a “downlink” beam may be either a transmit beam or a receivebeam, depending on the entity forming it. For example, if a base stationis forming the downlink beam to transmit a reference signal to a UE, thedownlink beam is a transmit beam. If the UE is forming the downlinkbeam, however, it is a receive beam to receive the downlink referencesignal. Similarly, an “uplink” beam may be either a transmit beam or areceive beam, depending on the entity forming it. For example, if a basestation is forming the uplink beam, it is an uplink receive beam, and ifa UE is forming the uplink beam, it is an uplink transmit beam.

In 5G, the frequency spectrum in which wireless nodes (e.g., basestations 102/180, UEs 104/182) operate is divided into multiplefrequency ranges, FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In amulti-carrier system, such as 5G, one of the carrier frequencies isreferred to as the “primary carrier” or “anchor carrier” or “primaryserving cell” or “PCell,” and the remaining carrier frequencies arereferred to as “secondary carriers” or “secondary serving cells” or“SCells.” In carrier aggregation, the anchor carrier is the carrieroperating on the primary frequency (e.g., FR1) utilized by a UE 104/182and the cell in which the UE 104/182 either performs the initial radioresource control (RRC) connection establishment procedure or initiatesthe RRC connection re-establishment procedure. The primary carriercarries all common and UE-specific control channels, and may be acarrier in a licensed frequency (however, this is not always the case).A secondary carrier is a carrier operating on a second frequency (e.g.,FR2) that may be configured once the RRC connection is establishedbetween the UE 104 and the anchor carrier and that may be used toprovide additional radio resources. In some cases, the secondary carriermay be a carrier in an unlicensed frequency. The secondary carrier maycontain only necessary signaling information and signals, for example,those that are UE-specific may not be present in the secondary carrier,since both primary uplink and downlink carriers are typicallyUE-specific. This means that different UEs 104/182 in a cell may havedifferent downlink primary carriers. The same is true for the uplinkprimary carriers. The network is able to change the primary carrier ofany UE 104/182 at any time. This is done, for example, to balance theload on different carriers. Because a “serving cell” (whether a PCell oran SCell) corresponds to a carrier frequency/component carrier overwhich some base station is communicating, the term “cell,” “servingcell,” “component carrier,” “carrier frequency,” and the like can beused interchangeably.

For example, still referring to FIG. 1 , one of the frequencies utilizedby the macro cell base stations 102 may be an anchor carrier (or“PCell”) and other frequencies utilized by the macro cell base stations102 and/or the mmW base station 180 may be secondary carriers(“SCells”). The simultaneous transmission and/or reception of multiplecarriers enables the UE 104/182 to significantly increase its datatransmission and/or reception rates. For example, two 20 MHz aggregatedcarriers in a multi-carrier system would theoretically lead to atwo-fold increase in data rate (i.e., 40 MHz), compared to that attainedby a single 20 MHz carrier.

The wireless communications system 100 may further include a UE 164 thatmay communicate with a macro cell base station 102 over a communicationlink 120 and/or the mmW base station 180 over a mmW communication link184. For example, the macro cell base station 102 may support a PCelland one or more SCells for the UE 164 and the mmW base station 180 maysupport one or more SCells for the UE 164.

In the example of FIG. 1 , one or more Earth orbiting satellitepositioning system (SPS) space vehicles (SVs) 112 (e.g., satellites) maybe used as an independent source of location information for any of theillustrated UEs (shown in FIG. 1 as a single UE 104 for simplicity). AUE 104 may include one or more dedicated SPS receivers specificallydesigned to receive SPS signals 124 for deriving geo locationinformation from the SVs 112. An SPS typically includes a system oftransmitters (e.g., SVs 112) positioned to enable receivers (e.g., UEs104) to determine their location on or above the Earth based, at leastin part, on signals (e.g., SPS signals 124) received from thetransmitters. Such a transmitter typically transmits a signal markedwith a repeating pseudo-random noise (PN) code of a set number of chips.While typically located in SVs 112, transmitters may sometimes belocated on ground-based control stations, base stations 102, and/orother UEs 104.

The use of SPS signals 124 can be augmented by various satellite-basedaugmentation systems (SBAS) that may be associated with or otherwiseenabled for use with one or more global and/or regional navigationsatellite systems. For example an SBAS may include an augmentationsystem(s) that provides integrity information, differential corrections,etc., such as the Wide Area Augmentation System (WAAS), the EuropeanGeostationary Navigation Overlay Service (EGNOS), the Multi-functionalSatellite Augmentation System (MSAS), the Global Positioning System(GPS) Aided Geo Augmented Navigation or GPS and Geo Augmented Navigationsystem (GAGAN), and/or the like. Thus, as used herein, an SPS mayinclude any combination of one or more global and/or regional navigationsatellite systems and/or augmentation systems, and SPS signals 124 mayinclude SPS, SPS-like, and/or other signals associated with such one ormore SPS.

The wireless communications system 100 may further include one or moreUEs, such as UE 190, that connects indirectly to one or morecommunication networks via one or more device-to-device (D2D)peer-to-peer (P2P) links (referred to as “sidelinks”). In the example ofFIG. 1 , UE 190 has a D2D P2P link 192 with one of the UEs 104 connectedto one of the base stations 102 (e.g., through which UE 190 mayindirectly obtain cellular connectivity) and a D2D P2P link 194 withWLAN STA 152 connected to the WLAN AP 150 (through which UE 190 mayindirectly obtain WLAN-based Internet connectivity). In an example, theD2D P2P links 192 and 194 may be supported with any well-known D2D RAT,such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, and so on.

FIG. 2A illustrates an example wireless network structure 200. Forexample, a 5GC 210 (also referred to as a Next Generation Core (NGC))can be viewed functionally as control plane functions 214 (e.g., UEregistration, authentication, network access, gateway selection, etc.)and user plane functions 212, (e.g., UE gateway function, access to datanetworks, IP routing, etc.) which operate cooperatively to form the corenetwork. User plane interface (NG-U) 213 and control plane interface(NG-C) 215 connect the gNB 222 to the 5GC 210 and specifically to thecontrol plane functions 214 and user plane functions 212. In anadditional configuration, an ng-eNB 224 may also be connected to the 5GC210 via NG-C 215 to the control plane functions 214 and NG-U 213 to userplane functions 212. Further, ng-eNB 224 may directly communicate withgNB 222 via a backhaul connection 223. In some configurations, a NextGeneration RAN (NG-RAN) 220 may only have one or more gNBs 222, whileother configurations include one or more of both ng-eNBs 224 and gNBs222. Either gNB 222 or ng-eNB 224 may communicate with UEs 204 (e.g.,any of the UEs depicted in FIG. 1 ). Another optional aspect may includelocation server 230, which may be in communication with the 5GC 210 toprovide location assistance for UEs 204. The location server 230 can beimplemented as a plurality of separate servers (e.g., physicallyseparate servers, different software modules on a single server,different software modules spread across multiple physical servers,etc.), or alternately may each correspond to a single server. Thelocation server 230 can be configured to support one or more locationservices for UEs 204 that can connect to the location server 230 via thecore network, 5GC 210, and/or via the Internet (not illustrated).Further, the location server 230 may be integrated into a component ofthe core network, or alternatively may be external to the core network.

FIG. 2B illustrates another example wireless network structure 250. A5GC 260 (which may correspond to 5GC 210 in FIG. 2A) can be viewedfunctionally as control plane functions, provided by an access andmobility management function (AMF) 264, and user plane functions,provided by a user plane function (UPF) 262, which operate cooperativelyto form the core network (i.e., 5GC 260). User plane interface 263 andcontrol plane interface 265 connect the ng-eNB 224 to the 5GC 260 andspecifically to UPF 262 and AMF 264, respectively. In an additionalconfiguration, a gNB 222 may also be connected to the 5GC 260 viacontrol plane interface 265 to AMF 264 and user plane interface 263 toUPF 262. Further, ng-eNB 224 may directly communicate with gNB 222 viathe backhaul connection 223, with or without gNB direct connectivity tothe 5GC 260. In some configurations, the NG-RAN 220 may only have one ormore gNBs 222, while other configurations include one or more of bothng-eNBs 224 and gNBs 222. Either gNB 222 or ng-eNB 224 may communicatewith UEs 204 (e.g., any of the UEs depicted in FIG. 1 ). The basestations of the NG-RAN 220 communicate with the AMF 264 over the N2interface and with the UPF 262 over the N3 interface.

The functions of the AMF 264 include registration management, connectionmanagement, reachability management, mobility management, lawfulinterception, transport for session management (SM) messages between theUE 204 and a session management function (SMF) 266, transparent proxyservices for routing SM messages, access authentication and accessauthorization, transport for short message service (SMS) messagesbetween the UE 204 and the short message service function (SMSF) (notshown), and security anchor functionality (SEAF). The AMF 264 alsointeracts with an authentication server function (AUSF) (not shown) andthe UE 204, and receives the intermediate key that was established as aresult of the UE 204 authentication process. In the case ofauthentication based on a UMTS (universal mobile telecommunicationssystem) subscriber identity module (USIM), the AMF 264 retrieves thesecurity material from the AUSF. The functions of the AMF 264 alsoinclude security context management (SCM). The SCM receives a key fromthe SEAF that it uses to derive access-network specific keys. Thefunctionality of the AMF 264 also includes location services managementfor regulatory services, transport for location services messagesbetween the UE 204 and an LMF 270 (which acts as a location server 230),transport for location services messages between the NG-RAN 220 and theLMF 270, evolved packet system (EPS) bearer identifier allocation forinterworking with the EPS, and UE 204 mobility event notification. Inaddition, the AMF 264 also supports functionalities for non-3GPP (ThirdGeneration Partnership Project) access networks.

Functions of the UPF 262 include acting as an anchor point forintra-/inter-RAT mobility (when applicable), acting as an externalprotocol data unit (PDU) session point of interconnect to a data network(not shown), providing packet routing and forwarding, packet inspection,user plane policy rule enforcement (e.g., gating, redirection, trafficsteering), lawful interception (user plane collection), traffic usagereporting, quality of service (QoS) handling for the user plane (e.g.,uplink/downlink rate enforcement, reflective QoS marking in thedownlink), uplink traffic verification (service data flow (SDF) to QoSflow mapping), transport level packet marking in the uplink anddownlink, downlink packet buffering and downlink data notificationtriggering, and sending and forwarding of one or more “end markers” tothe source RAN node. The UPF 262 may also support transfer of locationservices messages over a user plane between the UE 204 and a locationserver, such as an SLP 272.

The functions of the SMF 266 include session management, UE Internetprotocol (IP) address allocation and management, selection and controlof user plane functions, configuration of traffic steering at the UPF262 to route traffic to the proper destination, control of part ofpolicy enforcement and QoS, and downlink data notification. Theinterface over which the SMF 266 communicates with the AMF 264 isreferred to as the N11 interface.

Another optional aspect may include an LMF 270, which may be incommunication with the 5GC 260 to provide location assistance for UEs204. The LMF 270 can be implemented as a plurality of separate servers(e.g., physically separate servers, different software modules on asingle server, different software modules spread across multiplephysical servers, etc.), or alternately may each correspond to a singleserver. The LMF 270 can be configured to support one or more locationservices for UEs 204 that can connect to the LMF 270 via the corenetwork, 5GC 260, and/or via the Internet (not illustrated). The SLP 272may support similar functions to the LMF 270, but whereas the LMF 270may communicate with the AMF 264, NG-RAN 220, and UEs 204 over a controlplane (e.g., using interfaces and protocols intended to convey signalingmessages and not voice or data), the SLP 272 may communicate with UEs204 and external clients (not shown in FIG. 2B) over a user plane (e.g.,using protocols intended to carry voice and/or data like thetransmission control protocol (TCP) and/or IP).

FIGS. 3A, 3B, and 3C illustrate several example components (representedby corresponding blocks) that may be incorporated into a UE 302 (whichmay correspond to any of the UEs described herein), a base station 304(which may correspond to any of the base stations described herein), anda network entity 306 (which may correspond to or embody any of thenetwork functions described herein, including the location server 230and the LMF 270) to support the file transmission operations as taughtherein. It will be appreciated that these components may be implementedin different types of apparatuses in different implementations (e.g., inan ASIC, in a system-on-chip (SoC), etc.). The illustrated componentsmay also be incorporated into other apparatuses in a communicationsystem. For example, other apparatuses in a system may includecomponents similar to those described to provide similar functionality.Also, a given apparatus may contain one or more of the components. Forexample, an apparatus may include multiple transceiver components thatenable the apparatus to operate on multiple carriers and/or communicatevia different technologies.

The UE 302 and the base station 304 each include wireless wide areanetwork (WWAN) transceiver 310 and 350, respectively, providing meansfor communicating (e.g., means for transmitting, means for receiving,means for measuring, means for tuning, means for refraining fromtransmitting, etc.) via one or more wireless communication networks (notshown), such as an NR network, an LTE network, a GSM network, and/or thelike. The WWAN transceivers 310 and 350 may be connected to one or moreantennas 316 and 356, respectively, for communicating with other networknodes, such as other UEs, access points, base stations (e.g., eNBs,gNBs), etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc.)over a wireless communication medium of interest (e.g., some set oftime/frequency resources in a particular frequency spectrum). The WWANtransceivers 310 and 350 may be variously configured for transmittingand encoding signals 318 and 358 (e.g., messages, indications,information, and so on), respectively, and, conversely, for receivingand decoding signals 318 and 358 (e.g., messages, indications,information, pilots, and so on), respectively, in accordance with thedesignated RAT. Specifically, the WWAN transceivers 310 and 350 includeone or more transmitters 314 and 354, respectively, for transmitting andencoding signals 318 and 358, respectively, and one or more receivers312 and 352, respectively, for receiving and decoding signals 318 and358, respectively.

The UE 302 and the base station 304 also include, at least in somecases, one or more short-range wireless transceivers 320 and 360,respectively. The short-range wireless transceivers 320 and 360 may beconnected to one or more antennas 326 and 366, respectively, and providemeans for communicating (e.g., means for transmitting, means forreceiving, means for measuring, means for tuning, means for refrainingfrom transmitting, etc.) with other network nodes, such as other UEs,access points, base stations, etc., via at least one designated RAT(e.g., WiFi, LTE-D, Bluetooth®, Zigbee®, Z-Wave®, PC5, dedicatedshort-range communications (DSRC), wireless access for vehicularenvironments (WAVE), near-field communication (NFC), etc.) over awireless communication medium of interest. The short-range wirelesstransceivers 320 and 360 may be variously configured for transmittingand encoding signals 328 and 368 (e.g., messages, indications,information, and so on), respectively, and, conversely, for receivingand decoding signals 328 and 368 (e.g., messages, indications,information, pilots, and so on), respectively, in accordance with thedesignated RAT. Specifically, the short-range wireless transceivers 320and 360 include one or more transmitters 324 and 364, respectively, fortransmitting and encoding signals 328 and 368, respectively, and one ormore receivers 322 and 362, respectively, for receiving and decodingsignals 328 and 368, respectively. As specific examples, the short-rangewireless transceivers 320 and 360 may be WiFi transceivers, Bluetooth®transceivers, Zigbee® and/or Z-Wave® transceivers, NFC transceivers, orvehicle-to-vehicle (V2V) and/or vehicle-to-everything (V2X)transceivers.

Transceiver circuitry including at least one transmitter and at leastone receiver may comprise an integrated device (e.g., embodied as atransmitter circuit and a receiver circuit of a single communicationdevice) in some implementations, may comprise a separate transmitterdevice and a separate receiver device in some implementations, or may beembodied in other ways in other implementations. In an aspect, atransmitter may include or be coupled to a plurality of antennas (e.g.,antennas 316, 326, 356, 366), such as an antenna array, that permits therespective apparatus to perform transmit “beamforming,” as describedherein. Similarly, a receiver may include or be coupled to a pluralityof antennas (e.g., antennas 316, 326, 356, 366), such as an antennaarray, that permits the respective apparatus to perform receivebeamforming, as described herein. In an aspect, the transmitter andreceiver may share the same plurality of antennas (e.g., antennas 316,326, 356, 366), such that the respective apparatus can only receive ortransmit at a given time, not both at the same time. A wirelesscommunication device (e.g., one or both of the transceivers 310 and 320and/or 350 and 360) of the UE 302 and/or the base station 304 may alsocomprise a network listen module (NLM) or the like for performingvarious measurements.

The UE 302 and the base station 304 also include, at least in somecases, satellite positioning systems (SPS) receivers 330 and 370. TheSPS receivers 330 and 370 may be connected to one or more antennas 336and 376, respectively, and may provide means for receiving and/ormeasuring SPS signals 338 and 378, respectively, such as globalpositioning system (GPS) signals, global navigation satellite system(GLONASS) signals, Galileo signals, Beidou signals, Indian RegionalNavigation Satellite System (NAVIC), Quasi-Zenith Satellite System(QZSS), etc. The SPS receivers 330 and 370 may comprise any suitablehardware and/or software for receiving and processing SPS signals 338and 378, respectively. The SPS receivers 330 and 370 request informationand operations as appropriate from the other systems, and performscalculations necessary to determine positions of the UE 302 and the basestation 304 using measurements obtained by any suitable SPS algorithm.

The base station 304 and the network entity 306 each include at leastone network interfaces 380 and 390, respectively, providing means forcommunicating (e.g., means for transmitting, means for receiving, etc.)with other network entities. For example, the network interfaces 380 and390 (e.g., one or more network access ports) may be configured tocommunicate with one or more network entities via a wire-based orwireless backhaul connection. In some aspects, the network interfaces380 and 390 may be implemented as transceivers configured to supportwire-based or wireless signal communication. This communication mayinvolve, for example, sending and receiving messages, parameters, and/orother types of information.

The UE 302, the base station 304, and the network entity 306 alsoinclude other components that may be used in conjunction with theoperations as disclosed herein. The UE 302 includes processor circuitryimplementing a processing system 332 for providing functionalityrelating to, for example, wireless positioning, and for providing otherprocessing functionality. The base station 304 includes a processingsystem 384 for providing functionality relating to, for example,wireless positioning as disclosed herein, and for providing otherprocessing functionality. The network entity 306 includes a processingsystem 394 for providing functionality relating to, for example,wireless positioning as disclosed herein, and for providing otherprocessing functionality. The processing systems 332, 384, and 394 maytherefore provide means for processing, such as means for determining,means for calculating, means for receiving, means for transmitting,means for indicating, etc. In an aspect, the processing systems 332,384, and 394 may include, for example, one or more processors, such asone or more general purpose processors, multi-core processors, ASICs,digital signal processors (DSPs), field programmable gate arrays (FPGA),other programmable logic devices or processing circuitry, or variouscombinations thereof.

The UE 302, the base station 304, and the network entity 306 includememory circuitry implementing memory components 340, 386, and 396 (e.g.,each including a memory device), respectively, for maintaininginformation (e.g., information indicative of reserved resources,thresholds, parameters, and so on). The memory components 340, 386, and396 may therefore provide means for storing, means for retrieving, meansfor maintaining, etc. In some cases, the UE 302, the base station 304,and the network entity 306 may include RIS Modules 342, 388, and 398,respectively. The RIS Modules 342, 388, and 398 may be hardware circuitsthat are part of or coupled to the processing systems 332, 384, and 394,respectively, that, when executed, cause the UE 302, the base station304, and the network entity 306 to perform the functionality describedherein. In other aspects, the RIS Modules 342, 388, and 398 may beexternal to the processing systems 332, 384, and 394 (e.g., part of amodem processing system, integrated with another processing system,etc.). Alternatively, the RIS Modules 342, 388, and 398 may be memorymodules stored in the memory components 340, 386, and 396, respectively,that, when executed by the processing systems 332, 384, and 394 (or amodem processing system, another processing system, etc.), cause the UE302, the base station 304, and the network entity 306 to perform thefunctionality described herein. FIG. 3A illustrates possible locationsof the RIS Module 342, which may be part of the WWAN transceiver 310,the memory component 340, the processing system 332, or any combinationthereof, or may be a standalone component. FIG. 3B illustrates possiblelocations of the RIS Module 388, which may be part of the WWANtransceiver 350, the memory component 386, the processing system 384, orany combination thereof, or may be a standalone component. FIG. 3Cillustrates possible locations of the RIS Module 398, which may be partof the network interface(s) 390, the memory component 396, theprocessing system 394, or any combination thereof, or may be astandalone component.

The UE 302 may include one or more sensors 344 coupled to the processingsystem 332 to provide means for sensing or detecting movement and/ororientation information that is independent of motion data derived fromsignals received by the WWAN transceiver 310, the short-range wirelesstransceiver 320, and/or the SPS receiver 330. By way of example, thesensor(s) 344 may include an accelerometer (e.g., a micro-electricalmechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor(e.g., a compass), an altimeter (e.g., a barometric pressure altimeter),and/or any other type of movement detection sensor. Moreover, thesensor(s) 344 may include a plurality of different types of devices andcombine their outputs in order to provide motion information. Forexample, the sensor(s) 344 may use a combination of a multi-axisaccelerometer and orientation sensors to provide the ability to computepositions in 2D and/or 3D coordinate systems.

In addition, the UE 302 includes a user interface 346 providing meansfor providing indications (e.g., audible and/or visual indications) to auser and/or for receiving user input (e.g., upon user actuation of asensing device such a keypad, a touch screen, a microphone, and so on).Although not shown, the base station 304 and the network entity 306 mayalso include user interfaces.

Referring to the processing system 384 in more detail, in the downlink,IP packets from the network entity 306 may be provided to the processingsystem 384. The processing system 384 may implement functionality for anRRC layer, a packet data convergence protocol (PDCP) layer, a radio linkcontrol (RLC) layer, and a medium access control (MAC) layer. Theprocessing system 384 may provide RRC layer functionality associatedwith broadcasting of system information (e.g., master information block(MIB), system information blocks (SIBs)), RRC connection control (e.g.,RRC connection paging, RRC connection establishment, RRC connectionmodification, and RRC connection release), inter-RAT mobility, andmeasurement configuration for UE measurement reporting; PDCP layerfunctionality associated with header compression/decompression, security(ciphering, deciphering, integrity protection, integrity verification),and handover support functions; RLC layer functionality associated withthe transfer of upper layer PDUs, error correction through automaticrepeat request (ARQ), concatenation, segmentation, and reassembly of RLCservice data units (SDUs), re-segmentation of RLC data PDUs, andreordering of RLC data PDUs; and MAC layer functionality associated withmapping between logical channels and transport channels, schedulinginformation reporting, error correction, priority handling, and logicalchannel prioritization.

The transmitter 354 and the receiver 352 may implement Layer-1 (L1)functionality associated with various signal processing functions.Layer-1, which includes a physical (PHY) layer, may include errordetection on the transport channels, forward error correction (FEC)coding/decoding of the transport channels, interleaving, rate matching,mapping onto physical channels, modulation/demodulation of physicalchannels, and MIMO antenna processing. The transmitter 354 handlesmapping to signal constellations based on various modulation schemes(e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying(QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an orthogonalfrequency division multiplexing (OFDM) subcarrier, multiplexed with areference signal (e.g., pilot) in the time and/or frequency domain, andthen combined together using an inverse fast Fourier transform (IFFT) toproduce a physical channel carrying a time domain OFDM symbol stream.The OFDM symbol stream is spatially precoded to produce multiple spatialstreams. Channel estimates from a channel estimator may be used todetermine the coding and modulation scheme, as well as for spatialprocessing. The channel estimate may be derived from a reference signaland/or channel condition feedback transmitted by the UE 302. Eachspatial stream may then be provided to one or more different antennas356. The transmitter 354 may modulate an RF carrier with a respectivespatial stream for transmission.

At the UE 302, the receiver 312 receives a signal through its respectiveantenna(s) 316. The receiver 312 recovers information modulated onto anRF carrier and provides the information to the processing system 332.The transmitter 314 and the receiver 312 implement Layer-1 functionalityassociated with various signal processing functions. The receiver 312may perform spatial processing on the information to recover any spatialstreams destined for the UE 302. If multiple spatial streams aredestined for the UE 302, they may be combined by the receiver 312 into asingle OFDM symbol stream. The receiver 312 then converts the OFDMsymbol stream from the time-domain to the frequency domain using a fastFourier transform (FFT). The frequency domain signal comprises aseparate OFDM symbol stream for each subcarrier of the OFDM signal. Thesymbols on each subcarrier, and the reference signal, are recovered anddemodulated by determining the most likely signal constellation pointstransmitted by the base station 304. These soft decisions may be basedon channel estimates computed by a channel estimator. The soft decisionsare then decoded and de-interleaved to recover the data and controlsignals that were originally transmitted by the base station 304 on thephysical channel. The data and control signals are then provided to theprocessing system 332, which implements Layer-3 (L3) and Layer-2 (L2)functionality.

In the uplink, the processing system 332 provides demultiplexing betweentransport and logical channels, packet reassembly, deciphering, headerdecompression, and control signal processing to recover IP packets fromthe core network. The processing system 332 is also responsible forerror detection.

Similar to the functionality described in connection with the downlinktransmission by the base station 304, the processing system 332 providesRRC layer functionality associated with system information (e.g., MIB,SIBs) acquisition, RRC connections, and measurement reporting; PDCPlayer functionality associated with header compression/decompression,and security (ciphering, deciphering, integrity protection, integrityverification); RLC layer functionality associated with the transfer ofupper layer PDUs, error correction through ARQ, concatenation,segmentation, and reassembly of RLC SDUs, re-segmentation of RLC dataPDUs, and reordering of RLC data PDUs; and MAC layer functionalityassociated with mapping between logical channels and transport channels,multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing ofMAC SDUs from TBs, scheduling information reporting, error correctionthrough hybrid automatic repeat request (HARQ), priority handling, andlogical channel prioritization.

Channel estimates derived by the channel estimator from a referencesignal or feedback transmitted by the base station 304 may be used bythe transmitter 314 to select the appropriate coding and modulationschemes, and to facilitate spatial processing. The spatial streamsgenerated by the transmitter 314 may be provided to different antenna(s)316. The transmitter 314 may modulate an RF carrier with a respectivespatial stream for transmission.

The uplink transmission is processed at the base station 304 in a mannersimilar to that described in connection with the receiver function atthe UE 302. The receiver 352 receives a signal through its respectiveantenna(s) 356. The receiver 352 recovers information modulated onto anRF carrier and provides the information to the processing system 384.

In the uplink, the processing system 384 provides demultiplexing betweentransport and logical channels, packet reassembly, deciphering, headerdecompression, control signal processing to recover IP packets from theUE 302. IP packets from the processing system 384 may be provided to thecore network. The processing system 384 is also responsible for errordetection.

For convenience, the UE 302, the base station 304, and/or the networkentity 306 are shown in FIGS. 3A to 3C as including various componentsthat may be configured according to the various examples describedherein. It will be appreciated, however, that the illustrated blocks mayhave different functionality in different designs.

The various components of the UE 302, the base station 304, and thenetwork entity 306 may communicate with each other over data buses 334,382, and 392, respectively. The components of FIGS. 3A to 3C may beimplemented in various ways. In some implementations, the components ofFIGS. 3A to 3C may be implemented in one or more circuits such as, forexample, one or more processors and/or one or more ASICs (which mayinclude one or more processors). Here, each circuit may use and/orincorporate at least one memory component for storing information orexecutable code used by the circuit to provide this functionality. Forexample, some or all of the functionality represented by blocks 310 to346 may be implemented by processor and memory component(s) of the UE302 (e.g., by execution of appropriate code and/or by appropriateconfiguration of processor components). Similarly, some or all of thefunctionality represented by blocks 350 to 388 may be implemented byprocessor and memory component(s) of the base station 304 (e.g., byexecution of appropriate code and/or by appropriate configuration ofprocessor components). Also, some or all of the functionalityrepresented by blocks 390 to 398 may be implemented by processor andmemory component(s) of the network entity 306 (e.g., by execution ofappropriate code and/or by appropriate configuration of processorcomponents). For simplicity, various operations, acts, and/or functionsare described herein as being performed “by a UE,” “by a base station,”“by a network entity,” etc. However, as will be appreciated, suchoperations, acts, and/or functions may actually be performed by specificcomponents or combinations of components of the UE 302, base station304, network entity 306, etc., such as the processing systems 332, 384,394, the transceivers 310, 320, 350, and 360, the memory components 340,386, and 396, the RIS Modules 342, 388, and 398, etc.

Various frame structures may be used to support downlink and uplinktransmissions between network nodes (e.g., base stations and UEs). FIG.4A is a diagram 400 illustrating an example of a downlink framestructure, according to aspects of the disclosure. FIG. 4B is a diagram430 illustrating an example of channels within the downlink framestructure, according to aspects of the disclosure. FIG. 4C is a diagram450 illustrating an example of an uplink frame structure, according toaspects of the disclosure. FIG. 4D is a diagram 480 illustrating anexample of channels within an uplink frame structure, according toaspects of the disclosure. Other wireless communications technologiesmay have different frame structures and/or different channels.

LTE, and in some cases NR, utilizes OFDM on the downlink andsingle-carrier frequency division multiplexing (SC-FDM) on the uplink.Unlike LTE, however, NR has an option to use OFDM on the uplink as well.OFDM and SC-FDM partition the system bandwidth into multiple (K)orthogonal subcarriers, which are also commonly referred to as tones,bins, etc. Each subcarrier may be modulated with data. In general,modulation symbols are sent in the frequency domain with OFDM and in thetime domain with SC-FDM. The spacing between adjacent subcarriers may befixed, and the total number of subcarriers (K) may be dependent on thesystem bandwidth. For example, the spacing of the subcarriers may be 15kilohertz (kHz) and the minimum resource allocation (resource block) maybe 12 subcarriers (or 180 kHz). Consequently, the nominal FFT size maybe equal to 128, 256, 512, 1024, or 2048 for system bandwidth of 1.25,2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidthmay also be partitioned into subbands. For example, a subband may cover1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16subbands for system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz,respectively.

LTE supports a single numerology (subcarrier spacing (SCS), symbollength, etc.). In contrast, NR may support multiple numerologies (μ),for example, subcarrier spacings of 15 kHz (μ=0), 30 kHz (μ=1), 60 kHz(μ=2), 120 kHz (μ=3), and 240 kHz (μ=4) or greater may be available. Ineach subcarrier spacing, there are 14 symbols per slot. For 15 kHz SCS(μ=0), there is one slot per subframe, 10 slots per frame, the slotduration is 1 millisecond (ms), the symbol duration is 66.7 microseconds(μs), and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 50. For 30 kHz SCS (μ=¹), there are two slots per subframe, 20slots per frame, the slot duration is 0.5 ms, the symbol duration is33.3 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 100. For 60 kHz SCS (μ=2), there are four slots per subframe, 40slots per frame, the slot duration is 0.25 ms, the symbol duration is16.7 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 200. For 120 kHz SCS (μ=3), there are eight slots per subframe,80 slots per frame, the slot duration is 0.125 ms, the symbol durationis 8.33 μs, and the maximum nominal system bandwidth (in MHz) with a 4KFFT size is 400. For 240 kHz SCS (μ=4), there are 16 slots per subframe,160 slots per frame, the slot duration is 0.0625 ms, the symbol durationis 4.17 μs, and the maximum nominal system bandwidth (in MHz) with a 4KFFT size is 800.

In the example of FIGS. 4A to 4D, a numerology of 15 kHz is used. Thus,in the time domain, a 10 ms frame is divided into 10 equally sizedsubframes of 1 ms each, and each subframe includes one time slot. InFIGS. 4A to 4D, time is represented horizontally (on the X axis) withtime increasing from left to right, while frequency is representedvertically (on the Y axis) with frequency increasing (or decreasing)from bottom to top.

A resource grid may be used to represent time slots, each time slotincluding one or more time-concurrent resource blocks (RBs) (alsoreferred to as physical RBs (PRBs)) in the frequency domain. Theresource grid is further divided into multiple resource elements (REs).An RE may correspond to one symbol length in the time domain and onesubcarrier in the frequency domain. In the numerology of FIGS. 4A to 4D,for a normal cyclic prefix, an RB may contain 12 consecutive subcarriersin the frequency domain and seven consecutive symbols in the timedomain, for a total of 84 REs. For an extended cyclic prefix, an RB maycontain 12 consecutive subcarriers in the frequency domain and sixconsecutive symbols in the time domain, for a total of 72 REs. Thenumber of bits carried by each RE depends on the modulation scheme.

Some of the REs carry downlink reference (pilot) signals (DL-RS). TheDL-RS may include PRS, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB, etc.FIG. 4A illustrates example locations of REs carrying PRS (labeled “R”).

A collection of resource elements (REs) that are used for transmissionof PRS is referred to as a “PRS resource.” The collection of resourceelements can span multiple PRBs in the frequency domain and ‘N’ (such as1 or more) consecutive symbol(s) within a slot in the time domain. In agiven OFDM symbol in the time domain, a PRS resource occupiesconsecutive PRBs in the frequency domain.

The transmission of a PRS resource within a given PRB has a particularcomb size (also referred to as the “comb density”). A comb size ‘N’represents the subcarrier spacing (or frequency/tone spacing) withineach symbol of a PRS resource configuration. Specifically, for a combsize ‘N,’ PRS are transmitted in every Nth subcarrier of a symbol of aPRB. For example, for comb-4, for each symbol of the PRS resourceconfiguration, REs corresponding to every fourth subcarrier (such assubcarriers 0, 4, 8) are used to transmit PRS of the PRS resource.Currently, comb sizes of comb-2, comb-4, comb-6, and comb-12 aresupported for DL-PRS. FIG. 4A illustrates an example PRS resourceconfiguration for comb-6 (which spans six symbols). That is, thelocations of the shaded REs (labeled “R”) indicate a comb-6 PRS resourceconfiguration.

Currently, a DL-PRS resource may span 2, 4, 6, or 12 consecutive symbolswithin a slot with a fully frequency-domain staggered pattern. A DL-PRSresource can be configured in any higher layer configured downlink orflexible (FL) symbol of a slot. There may be a constant energy perresource element (EPRE) for all REs of a given DL-PRS resource. Thefollowing are the frequency offsets from symbol to symbol for comb sizes2, 4, 6, and 12 over 2, 4, 6, and 12 symbols. 2-symbol comb-2: {0, 1};4-symbol comb-2: {0, 1, 0, 1}; 6-symbol comb-2: {0, 1, 0, 1, 0, 1};12-symbol comb-2: {0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1}; 4-symbol comb-4:{0, 2, 1, 3}; 12-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3};6-symbol comb-6: {0, 3, 1, 4, 2, 5}; 12-symbol comb-6: {0, 3, 1, 4, 2,5, 0, 3, 1, 4, 2, 5}; and 12-symbol comb-12: {0, 6, 3, 9, 1, 7, 4, 10,2, 8, 5, 11}.

A “PRS resource set” is a set of PRS resources used for the transmissionof PRS signals, where each PRS resource has a PRS resource ID. Inaddition, the PRS resources in a PRS resource set are associated withthe same TRP. A PRS resource set is identified by a PRS resource set IDand is associated with a particular TRP (identified by a TRP ID). Inaddition, the PRS resources in a PRS resource set have the sameperiodicity, a common muting pattern configuration, and the samerepetition factor (such as “PRS-ResourceRepetitionFactor”) across slots.The periodicity is the time from the first repetition of the first PRSresource of a first PRS instance to the same first repetition of thesame first PRS resource of the next PRS instance. The periodicity mayhave a length selected from 2{circumflex over ( )}μ*{4, 5, 8, 10, 16,20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} slots, withμ=0, 1, 2, 3. The repetition factor may have a length selected from {1,2, 4, 6, 8, 16, 32} slots.

A PRS resource ID in a PRS resource set is associated with a single beam(or beam ID) transmitted from a single TRP (where a TRP may transmit oneor more beams). That is, each PRS resource of a PRS resource set may betransmitted on a different beam, and as such, a “PRS resource,” orsimply “resource,” also can be referred to as a “beam.” Note that thisdoes not have any implications on whether the TRPs and the beams onwhich PRS are transmitted are known to the UE.

A “PRS instance” or “PRS occasion” is one instance of a periodicallyrepeated time window (such as a group of one or more consecutive slots)where PRS are expected to be transmitted. A PRS occasion also may bereferred to as a “PRS positioning occasion,” a “PRS positioninginstance, a “positioning occasion,” “a positioning instance,” a“positioning repetition,” or simply an “occasion,” an “instance,” or a“repetition.”

A “positioning frequency layer” (also referred to simply as a “frequencylayer”) is a collection of one or more PRS resource sets across one ormore TRPs that have the same values for certain parameters.Specifically, the collection of PRS resource sets has the samesubcarrier spacing and cyclic prefix (CP) type (meaning all numerologiessupported for the PDSCH are also supported for PRS), the same Point A,the same value of the downlink PRS bandwidth, the same start PRB (andcenter frequency), and the same comb-size. The Point A parameter takesthe value of the parameter “ARFCN-ValueNR” (where “ARFCN” stands for“absolute radio-frequency channel number”) and is an identifier/codethat specifies a pair of physical radio channel used for transmissionand reception. The downlink PRS bandwidth may have a granularity of fourPRBs, with a minimum of 24 PRBs and a maximum of 272 PRBs. Currently, upto four frequency layers have been defined, and up to two PRS resourcesets may be configured per TRP per frequency layer.

The concept of a frequency layer is somewhat like the concept ofcomponent carriers and bandwidth parts (BWPs), but different in thatcomponent carriers and BWPs are used by one base station (or a macrocell base station and a small cell base station) to transmit datachannels, while frequency layers are used by several (usually three ormore) base stations to transmit PRS. A UE may indicate the number offrequency layers it can support when it sends the network itspositioning capabilities, such as during an LTE positioning protocol(LPP) session. For example, a UE may indicate whether it can support oneor four positioning frequency layers.

FIG. 4B illustrates an example of various channels within a downlinkslot of a radio frame. In NR, the channel bandwidth, or systembandwidth, is divided into multiple BWPs. A BWP is a contiguous set ofPRBs selected from a contiguous subset of the common RBs for a givennumerology on a given carrier. Generally, a maximum of four BWPs can bespecified in the downlink and uplink. That is, a UE can be configuredwith up to four BWPs on the downlink, and up to four BWPs on the uplink.Only one BWP (uplink or downlink) may be active at a given time, meaningthe UE may only receive or transmit over one BWP at a time. On thedownlink, the bandwidth of each BWP should be equal to or greater thanthe bandwidth of the SSB, but it may or may not contain the SSB.

Referring to FIG. 4B, a primary synchronization signal (PSS) is used bya UE to determine subframe/symbol timing and a physical layer identity.A secondary synchronization signal (SSS) is used by a UE to determine aphysical layer cell identity group number and radio frame timing. Basedon the physical layer identity and the physical layer cell identitygroup number, the UE can determine a PCI. Based on the PCI, the UE candetermine the locations of the aforementioned DL-RS. The physicalbroadcast channel (PBCH), which carries an MIB, may be logically groupedwith the PSS and SSS to form an SSB (also referred to as an SS/PBCH).The MIB provides a number of RBs in the downlink system bandwidth and asystem frame number (SFN). The physical downlink shared channel (PDSCH)carries user data, broadcast system information not transmitted throughthe PBCH, such as system information blocks (SIBs), and paging messages.

The physical downlink control channel (PDCCH) carries downlink controlinformation (DCI) within one or more control channel elements (CCEs),each CCE including one or more RE group (REG) bundles (which may spanmultiple symbols in the time domain), each REG bundle including one ormore REGs, each REG corresponding to 12 resource elements (one resourceblock) in the frequency domain and one OFDM symbol in the time domain.The set of physical resources used to carry the PDCCH/DCI is referred toin NR as the control resource set (CORESET). In NR, a PDCCH is confinedto a single CORESET and is transmitted with its own DMRS. This enablesUE-specific beamforming for the PDCCH.

In the example of FIG. 4B, there is one CORESET per BWP, and the CORESETspans three symbols (although it may be only one or two symbols) in thetime domain. Unlike LTE control channels, which occupy the entire systembandwidth, in NR, PDCCH channels are localized to a specific region inthe frequency domain (i.e., a CORESET). Thus, the frequency component ofthe PDCCH shown in FIG. 4B is illustrated as less than a single BWP inthe frequency domain. Note that although the illustrated CORESET iscontiguous in the frequency domain, it need not be. In addition, theCORESET may span less than three symbols in the time domain.

The DCI within the PDCCH carries information about uplink resourceallocation (persistent and non-persistent) and descriptions aboutdownlink data transmitted to the UE, referred to as uplink and downlinkgrants, respectively. More specifically, the DCI indicates the resourcesscheduled for the downlink data channel (e.g., PDSCH) and the uplinkdata channel (e.g., PUSCH). Multiple (e.g., up to eight) DCIs can beconfigured in the PDCCH, and these DCIs can have one of multipleformats. For example, there are different DCI formats for uplinkscheduling, for downlink scheduling, for uplink transmit power control(TPC), etc. A PDCCH may be transported by 1, 2, 4, 8, or 16 CCEs inorder to accommodate different DCI payload sizes or coding rates.

As illustrated in FIG. 4C, some of the REs (labeled “R”) carry DMRS forchannel estimation at the receiver (e.g., a base station, another UE,etc.). A UE may additionally transmit SRS in, for example, the lastsymbol of a slot. The SRS may have a comb structure, and a UE maytransmit SRS on one of the combs. In the example of FIG. 4C, theillustrated SRS is comb-2 over one symbol. The SRS may be used by a basestation to obtain the channel state information (CSI) for each UE. CSIdescribes how an RF signal propagates from the UE to the base stationand represents the combined effect of scattering, fading, and powerdecay with distance. The system uses the SRS for resource scheduling,link adaptation, massive MIMO, beam management, etc.

Currently, an SRS resource may span 1, 2, 4, 8, or 12 consecutivesymbols within a slot with a comb size of comb-2, comb-4, or comb-8. Thefollowing are the frequency offsets from symbol to symbol for the SRScomb patterns that are currently supported. 1-symbol comb-2: {0};2-symbol comb-2: {0, 1}; 4-symbol comb-2: {0, 1, 0, 1}; 4-symbol comb-4:{0, 2, 1, 3}; 8-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3}; 12-symbolcomb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3}; 4-symbol comb-8: {0, 4, 2,6}; 8-symbol comb-8: {0, 4, 2, 6, 1, 5, 3, 7}; and 12-symbol comb-8: {0,4, 2, 6, 1, 5, 3, 7, 0, 4, 2, 6}.

A collection of resource elements that are used for transmission of SRSis referred to as an “SRS resource,” and may be identified by theparameter “SRS-ResourceId.” The collection of resource elements can spanmultiple PRBs in the frequency domain and N (e.g., one or more)consecutive symbol(s) within a slot in the time domain. In a given OFDMsymbol, an SRS resource occupies consecutive PRBs. An “SRS resource set”is a set of SRS resources used for the transmission of SRS signals, andis identified by an SRS resource set ID (“SRS-ResourceSetId”).

Generally, a UE transmits SRS to enable the receiving base station(either the serving base station or a neighboring base station) tomeasure the channel quality between the UE and the base station.However, SRS can also be specifically configured as uplink positioningreference signals for uplink-based positioning procedures, such asuplink time difference of arrival (UL-TDOA), round-trip-time (RTT),uplink angle-of-arrival (UL-AoA), etc. As used herein, the term “SRS”may refer to SRS configured for channel quality measurements or SRSconfigured for positioning purposes. The former may be referred toherein as “SRS-for-communication” and/or the latter may be referred toas “SRS-for-positioning” when needed to distinguish the two types ofSRS.

Several enhancements over the previous definition of SRS have beenproposed for SRS-for-positioning (also referred to as “UL-PRS”), such asa new staggered pattern within an SRS resource (except forsingle-symbol/comb-2), a new comb type for SRS, new sequences for SRS, ahigher number of SRS resource sets per component carrier, and a highernumber of SRS resources per component carrier. In addition, theparameters “SpatialRelationInfo” and “PathLossReference” are to beconfigured based on a downlink reference signal or SSB from aneighboring TRP. Further still, one SRS resource may be transmittedoutside the active BWP, and one SRS resource may span across multiplecomponent carriers. Also, SRS may be configured in RRC connected stateand only transmitted within an active BWP. Further, there may be nofrequency hopping, no repetition factor, a single antenna port, and newlengths for SRS (e.g., 8 and 12 symbols). There also may be open-looppower control and not closed-loop power control, and comb-8 (i.e., anSRS transmitted every eighth subcarrier in the same symbol) may be used.Lastly, the UE may transmit through the same transmit beam from multipleSRS resources for UL-AoA. All of these are features that are additionalto the current SRS framework, which is configured through RRC higherlayer signaling (and potentially triggered or activated through MACcontrol element (CE) or DCI).

FIG. 4D illustrates an example of various channels within an uplink slotof a frame, according to aspects of the disclosure. A random-accesschannel (RACH), also referred to as a physical random-access channel(PRACH), may be within one or more slots within a frame based on thePRACH configuration. The PRACH may include six consecutive RB pairswithin a slot. The PRACH allows the UE to perform initial system accessand achieve uplink synchronization. A physical uplink control channel(PUCCH) may be located on edges of the uplink system bandwidth. ThePUCCH carries uplink control information (UCI), such as schedulingrequests, CSI reports, a channel quality indicator (CQI), a precodingmatrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACKfeedback. The physical uplink shared channel (PUSCH) carries data, andmay additionally be used to carry a buffer status report (BSR), a powerheadroom report (PHR), and/or UCI.

Note that the terms “positioning reference signal” and “PRS” generallyrefer to specific reference signals that are used for positioning in NRand LTE systems. However, as used herein, the terms “positioningreference signal” and “PRS” may also refer to any type of referencesignal that can be used for positioning, such as but not limited to, PRSas defined in LTE and NR, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB,SRS, UL-PRS, etc. In addition, the terms “positioning reference signal”and “PRS” may refer to downlink or uplink positioning reference signals,unless otherwise indicated by the context. If needed to furtherdistinguish the type of PRS, a downlink positioning reference signal maybe referred to as a “DL-PRS,” and an uplink positioning reference signal(e.g., an SRS-for-positioning, PTRS) may be referred to as an “UL-PRS.”In addition, for signals that may be transmitted in both the uplink anddownlink (e.g., DMRS, PTRS), the signals may be prepended with “UL” or“DL” to distinguish the direction. For example, “UL-DMRS” may bedifferentiated from “DL-DMRS.”

NR supports a number of cellular network-based positioning technologies,including downlink-based, uplink-based, and downlink-and-uplink-basedpositioning methods. Downlink-based positioning methods include observedtime difference of arrival (OTDOA) in LTE, downlink time difference ofarrival (DL-TDOA) in NR, and downlink angle-of-departure (DL-AoD) in NR.In an OTDOA or DL-TDOA positioning procedure, a UE measures thedifferences between the times of arrival (TOAs) of reference signals(e.g., PRS, TRS, CSI-RS, SSB, etc.) received from pairs of basestations, referred to as reference signal time difference (RSTD) or timedifference of arrival (TDOA) measurements, and reports them to apositioning entity. More specifically, the UE receives the identifiers(IDs) of a reference base station (e.g., a serving base station) andmultiple non-reference base stations in assistance data. The UE thenmeasures the RSTD between the reference base station and each of thenon-reference base stations. Based on the known locations of theinvolved base stations and the RSTD measurements, the positioning entitycan estimate the UE's location.

For DL-AoD positioning, the positioning entity uses a beam report fromthe UE of received signal strength measurements of multiple downlinktransmit beams to determine the angle(s) between the UE and thetransmitting base station(s). The positioning entity can then estimatethe location of the UE based on the determined angle(s) and the knownlocation(s) of the transmitting base station(s).

Uplink-based positioning methods include uplink time difference ofarrival (UL-TDOA) and uplink angle-of-arrival (UL-AoA). UL-TDOA issimilar to DL-TDOA, but is based on uplink reference signals (e.g., SRS)transmitted by the UE. For UL-AoA positioning, one or more base stationsmeasure the received signal strength of one or more uplink referencesignals (e.g., SRS) received from a UE on one or more uplink receivebeams. The positioning entity uses the signal strength measurements andthe angle(s) of the receive beam(s) to determine the angle(s) betweenthe UE and the base station(s). Based on the determined angle(s) and theknown location(s) of the base station(s), the positioning entity canthen estimate the location of the UE.

Downlink-and-uplink-based positioning methods include enhanced cell-ID(E-CID) positioning and multi-round-trip-time (RTT) positioning (alsoreferred to as “multi-cell RTT”). In an RTT procedure, an initiator (abase station or a UE) transmits an RTT measurement signal (e.g., a PRSor SRS) to a responder (a UE or base station), which transmits an RTTresponse signal (e.g., an SRS or PRS) back to the initiator. The RTTresponse signal includes the difference between the TOA of the RTTmeasurement signal and the transmission time of the RTT response signal,referred to as the reception-to-transmission (Rx-Tx) time difference.The initiator calculates the difference between the transmission time ofthe RTT measurement signal and the TOA of the RTT response signal,referred to as the transmission-to-reception (Tx-Rx) time difference.The propagation time (also referred to as the “time of flight”) betweenthe initiator and the responder can be calculated from the Tx-Rx andRx-Tx time differences. Based on the propagation time and the knownspeed of light, the distance between the initiator and the responder canbe determined. For multi-RTT positioning, a UE performs an RTT procedurewith multiple base stations to enable its location to be triangulatedbased on the known locations of the base stations. RTT and multi-RTTmethods can be combined with other positioning techniques, such asUL-AoA and DL-AoD, to improve location accuracy.

The E-CID positioning method is based on radio resource management (RRM)measurements. In E-CID, the UE reports the serving cell ID, the timingadvance (TA), and the identifiers, estimated timing, and signal strengthof detected neighbor base stations. The location of the UE is thenestimated based on this information and the known locations of the basestation(s).

To assist positioning operations, a location server (e.g., locationserver 230, LMF 270, SLP 272) may provide assistance data to the UE. Forexample, the assistance data may include identifiers of the basestations (or the cells/TRPs of the base stations) from which to measurereference signals, the reference signal configuration parameters (e.g.,the number of consecutive positioning subframes, periodicity ofpositioning subframes, muting sequence, frequency hopping sequence,reference signal identifier, reference signal bandwidth, etc.), and/orother parameters applicable to the particular positioning method.Alternatively, the assistance data may originate directly from the basestations themselves (e.g., in periodically broadcasted overheadmessages, etc.). in some cases, the UE may be able to detect neighbornetwork nodes itself without the use of assistance data.

In the case of an OTDOA or DL-TDOA positioning procedure, the assistancedata may further include an expected RSTD value and an associateduncertainty, or search window, around the expected RSTD. In some cases,the value range of the expected RSTD may be +/−500 microseconds (μs). Insome cases, when any of the resources used for the positioningmeasurement are in FR1, the value range for the uncertainty of theexpected RSTD may be +/−32 μs. In other cases, when all of the resourcesused for the positioning measurement(s) are in FR2, the value range forthe uncertainty of the expected RSTD may be +/−8 μs.

A location estimate may be referred to by other names, such as aposition estimate, location, position, position fix, fix, or the like. Alocation estimate may be geodetic and comprise coordinates (e.g.,latitude, longitude, and possibly altitude) or may be civic and comprisea street address, postal address, or some other verbal description of alocation. A location estimate may further be defined relative to someother known location or defined in absolute terms (e.g., using latitude,longitude, and possibly altitude). A location estimate may include anexpected error or uncertainty (e.g., by including an area or volumewithin which the location is expected to be included with some specifiedor default level of confidence).

FIG. 5 illustrates an exemplary wireless communications system 600according to aspects of the disclosure. In FIG. 5 , eNB₁, eNB₂ and eNB₃are synchronized with each other, such that TOA (e.g., TDOA)measurements (denoted as T₁, T₂ and T₃) can be used to generate apositioning estimate for a UE. Multiple TDOA measurements may be usedfor triangulation (e.g., 4 or more cells or eNBs). In TDOA-basedpositioning schemes, network synchronization error is the mainbottleneck in terms of positioning accuracy.

Another positioning technique that requires cell (or satellite)synchronization is based on Observed Time Difference Of Arrival (OTDOA).One example OTDOA-based positioning scheme is GPS, which is limited toan accuracy of 50-100 ns (e.g., 15-30 meters).

FIG. 6 illustrates an example system 600 for wireless communicationusing a reconfigurable intelligent surface (RIS) 610, according toaspects of the disclosure. An RIS (e.g., RIS 610) is a two-dimensionalsurface comprising a large number of low-cost, low-power near-passivereflecting elements whose properties are reconfigurable (by software)rather than static. For example, by carefully tuning the phase shifts ofthe reflecting elements (using software), the scattering, absorption,reflection, and diffraction properties of an RIS can be changed overtime. In that way, the electromagnetic (EM) properties of an RIS can beengineered to collect wireless signals from a transmitter (e.g., a basestation, a UE, etc.) and passively beamform them towards a targetreceiver (e.g., another base station, another UE, etc.). In the exampleof FIG. 6 , a first base station 602-1 controls the reflectiveproperties of an RIS 610 in order to communicate with a first UE 604-1.

The goal of RIS technology is to create smart radio environments, wherethe wireless propagation conditions are co-engineered with the physicallayer signaling. This enhanced functionality of the system 600 canprovide technical benefits in a number of scenarios.

As a first example scenario, as shown in FIG. 6 , the first base station602-1 (e.g., any of the base station described herein) is attempting totransmit downlink wireless signals to the first UE 604-1 and a second UE604-2 (e.g., any two of the UEs described herein, collectively, UEs 604)on a plurality of downlink transmit beams, labeled “0,” “1,” “2,” and“3.” However, unlike the second UE 604-2, because the first UE 604-1 isbehind an obstacle 620 (e.g., a building, a hill, or another type ofobstacle), it cannot receive the wireless signal on what would otherwisebe the line-of-sight (LOS) beam from the first base station 602-1, thatis, the downlink transmit beam labeled “2.” In this scenario, the firstbase station 602-1 may instead use the downlink transmit beam labeled“1” to transmit the wireless signal to the RIS 610, and configure theRIS 610 to reflect/beamform the incoming wireless signal towards thefirst UE 604-1. The first base station 602-1 can thereby transmit thewireless signal around the obstacle 620.

Note that the first base station 602-1 may also configure the RIS 610for the first UE's 604-1 use in the uplink. In that case, the first basestation 602-1 may configure the RIS 610 to reflect an uplink signal fromthe first UE 604-1 to the first base station 602-1, thereby enabling thefirst UE 604-1 to transmit the uplink signal around the obstacle 620.

As another example scenario in which system 600 can provide a technicaladvantage, the first base station 602-1 may be aware that the obstacle620 may create a “dead zone,” that is, a geographic area in which thedownlink wireless signals from the first base station 602-1 are tooattenuated to be reliably detected by a UE within that area (e.g., thefirst UE 604-1). In this scenario, the first base station 602-1 mayconfigure the RIS 610 to reflect downlink wireless signals into the deadzone in order to provide coverage to UEs that may be located there,including UEs about which the first base station 602-1 is not aware.

An RIS (e.g., RIS 610) may be designed to operate in either a first mode(referred to as “Mode 1”), in which the RIS operates as a reconfigurablemirror, or a second mode (referred to as “Mode 2”), in which the RISoperates as a receiver and transmitter (similar to the amplify andforward functionality of a relay). Some RIS may be designed to be ableto operate in either Mode 1 or Mode 2, while other RIS may be designedto only operate in Mode 1. Mode 1 RIS are assumed to have a negligiblehardware group delay, whereas Mode 2 RIS have a non-negligible hardwaregroup delay. This is because Mode 2-capable RIS are equipped withbaseband processing capability in order to forward (and amplify ifneeded) a received signal. In an aspect, the first base station 602-1may indicate whether the RIS 610 is a Mode 1 RIS or a Mode 2 RIS. In thelatter case, the first base station 602-1 may compute and provide anassociated reception-to-transmission (Rx-Tx) time difference for the RIS610. In some designs, the RIS 610 may compute and/or report its Rx-Txtime difference, and the first base station 602-1 may report thiscapability.

FIG. 6 also illustrates a second base station 602-2 that may transmitdownlink wireless signals to one or both of the UEs 604. As an example,the first base station 602-1 may be a serving base station for the UEs604 and the second base station 602-2 may be a neighboring base station.The second base station 602-2 may transmit downlink positioningreference signals to one or both of the UEs 604 as part of a positioningprocedure involving the UE(s) 604. Alternatively or additionally, thesecond base station 602-2 may be a secondary cell for one or both of theUEs 604. In some cases, the second base station 602-2 may also be ableto reconfigure the RIS 610, provided it is not being controlled by thefirst base station 602-1 at the time.

FIG. 7 is a diagram of an example architecture of a RIS 700, accordingto aspects of the disclosure. The RIS 700, which may correspond to RIS610 in FIG. 6 , may be a Mode 1 RIS. As shown in FIG. 7 , the RIS 700primarily consists of a planar surface 710 and a controller 720. Theplanar surface 710 may be constructed of one or more layers of material.In the example of FIG. 7 , the planar surface 710 may consist of threelayers. In this case, the outer layer has a large number of reflectingelements 712 printed on a dielectric substrate to directly act on theincident signals. The middle layer is a copper panel to avoidsignal/energy leakage. The last layer is a circuit board that is usedfor tuning the reflection coefficients of the reflecting elements 712and is operated by the controller 720. The controller 720 may be alow-power processor, such as a field-programmable gate array (FPGA).

In a typical operating scenario, the optimal reflection coefficients ofthe RIS 700 is calculated at the base station (e.g., the first basestation 602-1 in FIG. 6 ), and then sent to the controller 720 through adedicated feedback link. The design of the reflection coefficientsdepends on the channel state information (CSI), which is only updatedwhen the CSI changes, which is on a much longer time scale than the datasymbol duration. As such, low-rate information exchange is sufficientfor the dedicated control link, which can be implemented using low-costcopper lines or simple cost-efficient wireless transceivers.

Each reflecting element 712 is coupled to a positive-intrinsic negative(PIN) diode 714. In addition, a biasing line 716 connects eachreflecting element 712 in a column to the controller 720. By controllingthe voltage through the biasing line 716, the PIN diodes 714 can switchbetween ‘on’ and ‘off’ modes. This can realize a phase shift differenceof 1 (pi) in radians. To increase the number of phase shift levels, morePIN diodes 712 can be coupled to each reflecting element 712.

An RIS, such as RIS 700, has important advantages for practicalimplementations. For example, the reflecting elements 712 only passivelyreflect the incoming signals without any sophisticated signal processingoperations that would require RF transceiver hardware. As such, comparedto conventional active transmitters, the RIS 700 can operate withseveral orders of magnitude lower cost in terms of hardware and powerconsumption. Additionally, due to the passive nature of the reflectingelements 712, an RIS 700 can be fabricated with light weight and limitedlayer thickness, and as such, can be readily installed on a wall, aceiling, signage, a street lamp, etc. Further, the RIS 700 naturallyoperates in full-duplex (FD) mode without self-interference orintroducing thermal noise. Therefore, it can achieve higher spectralefficiency than active half-duplex (HD) relays, despite their lowersignal processing complexity than that of active FD relays requiringsophisticated self-interference cancelation.

As noted above, various device types may be characterized as UEs.Starting in 3GPP Rel. 17, a number of these UE types (so-called low-tierUEs) are being allocated a new UE classification denoted as ReducedCapability (‘RedCap’) or ‘NR-Light’. Examples of UE types that fallunder the RedCap classification include wearable devices (e.g., smartwatches, etc.), industrial sensors, video cameras (e.g., surveillancecameras, etc.), and so on. Generally, the UE types grouped under theRedCap classification are associated with lower communicative capacity.For example, relative to ‘normal’ UEs (e.g., UEs not classified asRedCap), RedCap UEs may be limited in terms of maximum bandwidth (e.g.,5 MHz, 10 MHz, 20 MHz, etc.), maximum transmission power (e.g., 20 dBm,14 dBm, etc.), number of receive antennas (e.g., 1 receive antenna, 2receive antennas, etc.), and so on. Some RedCap UEs may also besensitive in terms of power consumption (e.g., requiring a long batterylife, such as several years) and may be highly mobile. Moreover, in somedesigns, it is generally desirable for RedCap UEs to co-exist with UEsimplementing protocols such as eMBB, URLLC, LTE NB-IoT/MTC, and so on.

Due to its limited capability, a RedCap UE may have difficulty inhearing or detecting PRS, particularly from non-serving gNBs which maybe further away from the RedCap UE than a serving gNB (e.g., due tolimited reception bandwidth, Rx antennas, baseband processingcapability, etc.). Likewise, the RedCap UE may be associated with poorSRS measurements (e.g., limited capability to measure UL-SRS-P at one ormore neighbor gNBs, limited capability to measure UL-SRS-P reflectionsoff RIS by the UE itself, etc.). In some designs, low-power UEpositioning schemes may be implemented for RedCap UEs. However, suchimplementations generally require the RedCap UEs to be in coverage(e.g., UL and DL coverage) of a serving gNB as well as non-serving gNBs.In some designs, RISs can be treated as positioning anchors forRIS-aided positioning of UEs (e.g., particularly for indoor scenarios).

A RIS aided DL-TDOA positioning scheme is one approach towardsovercoming some of the challenges of cell coverage and network syncerror, e.g., for RedCap UEs. Compared with DL-TDOA, UL-TDOA positioningschemes may have the benefits of lower latency and lower powerconsumption, as UE may only to transmit a single shot SRS to the gNBswithout measurement report. However, UL-TDOA positioning schemes maystill be difficult to implement in terms of cell coverage and networksync error.

Aspects of the disclosure are thereby directed to RIS-aided positioningfor UL-TDOA (e.g., as used herein, UL-TDOA includes sidelink or SL-TDOAin a scenario where another UE performs the SRS measurements). Suchaspects may provide various technical advantages, such as obtaining theUL-TDOA benefits of lower latency and lower power consumption whilereducing the above-noted problems associated with legacy UL-TDOApositioning schemes, such as cell coverage and network sync error.

FIG. 8 illustrates an exemplary process 800 of communications accordingto an aspect of the disclosure. The process 800 of FIG. 8 is performedby a wireless node, which may correspond to UE 302 (e.g., a relay,anchor or reference UE associated with a known location, e.g., from arecent positioning fix), or BS 304 (e.g., a serving gNB).

Referring to FIG. 8 , at 810, the wireless node (e.g., receiver 312 or322 or 352 or 362, RIS module 342 or 388, processing system 332 or 384,etc.) measures a first time of arrival (TOA) of a first soundingreference signal for positioning (SRS-P) from a UE. Here, the UEcorresponds to a target UE for which a positioning estimate is desired.

Referring to FIG. 8 , at 820, the wireless node (e.g., receiver 312 or322 or 352 or 362, RIS module 342 or 388, processing system 332 or 384,etc.) measures a second TOA of a reflection of a second SRS-P from theUE off of a first reconfigurable intelligent surface (RIS). In somedesigns, the second SRS-P may be the same or different from the firstSRS-P. In some designs, where the first and second SRS-Ps are different,the transmission times of the first and second SRS-Ps may be associatedwith a known offset time.

Referring to FIG. 8 , at 830, the wireless node (e.g., receiver 312 or322 or 352 or 362, RIS module 342 or 388, processing system 332 or 384,etc.) measures a third TOA of a reflection of a third SRS-P from the UEoff of a second RIS. In some designs, the third SRS-P may be the same ordifferent from the first and/or second SRS-Ps. In some designs, wherethe third SRS-P is different than the first and/or second SRS-Ps, thetransmission time of the third SRS-P relative to the first and/or secondSRS-Ps may be associated with known offset time(s).

Referring to FIG. 8 , at 840, the wireless node (e.g., transmitter 314or 324 or 354 or 364, data bus 334 or 382, network interface(s) 380,etc.) transmits, to a position estimation entity, measurementinformation based on the first, second and third TOAs. In some designs,the position estimation entity corresponds to the UE, a serving basestation of the UE, a location management function (LMF), a locationserver, or a combination thereof. In some designs, the positionestimation entity may correspond to the wireless node itself (e.g.,reference or anchor UE, gNB for LMF integrated in RAN, etc.), in whichcase the transmission of the measurement information corresponds to atransfer of the measurement information from one logical component ofthe wireless node to another logical component of the wireless node. Insome designs, the measurement information may include the raw TOAsmeasured at 810-830, while in other designs, the measurement informationmay be processed from the raw TOAs (e.g., TDOAs, RSTDs, etc.)

FIG. 9 illustrates an exemplary process 900 of communications accordingto an aspect of the disclosure. The process 900 of FIG. 9 is performedby a position estimation entity, which may correspond to UE 302 (e.g., atarget UE for which a positioning fix is desired, a relay, anchor orreference UE associated with a known location, e.g., from a recentpositioning fix), or BS 304 (e.g., a serving gNB), a location managementfunction (LMF), a location server, or a combination thereof.

Referring to FIG. 9 , at 910, the position estimation entity (e.g.,receiver 312 or 322 or 352 or 362, network interface(s) 380 or 390, databus 334 or 382, etc.) receives, from a wireless node, measurementinformation based on a first TOA of a first SRS-P from a UE, a secondTOA of a reflection of a second SRS-P from the UE off of a first RIS,and a third TOA of a reflection of a third SRS-P from the UE off of asecond RIS. For example, the measurement information received at 910 maycorrespond to the measurement information transmitted at 840 of FIG. 8 .

Referring to FIG. 9 , at 920, the position estimation entity (e.g., RISmodule 342 or 388 or 398, processing system 332 or 388 or 398, etc.)determines a positioning estimate of the UE based at least in part onthe measurement information.

FIG. 10 illustrates an example implementation 1000 of the processes800-900 of FIGS. 8-9 in accordance with an aspect of the disclosure. Inparticular, FIG. 10 depicts an example where the first, second and thirdSRS-Ps are the same SRS-P. FIG. 10 further depicts an example where thefirst RIS (RIS 1) and the second RIS (2) are Mode 1 RISs (e.g., withouta group delay, or with a negligible group delay below some threshold).

Referring to FIG. 10 , at t₁, the UE transmits an SRS-P 1002 along path1 to the wireless node (denoted as 1002_1), along path 2 to RIS 1(denoted as 1002_2), and along path 3 to RIS 2 (denoted as 1002_3).SRS-P 1002_1 arrives at the wireless node and is measured at TOA₁. SRS-P1002_2 is reflected off of RIS 1 at t₂ as SRS-P reflection 1004, andSRS-P reflection 1004 arrives at the wireless node and is measured atTOA₂. SRS-P 1002_3 is reflected off of RIS 2 at t₃ as SRS-P reflection1006, and SRS-P reflection 1006 arrives at the wireless node and ismeasured at TOA₃. In some designs, the respective TOAs may be processedas RSTDs and sent in a measurement report to a position estimationentity. However, the raw TOA data may alternatively be transmitted tothe position estimation entity in other designs.

FIG. 11 illustrates an example implementation 1100 of the processes800-900 of FIGS. 8-9 in accordance with another aspect of thedisclosure. In particular, FIG. 11 depicts an example where the firstand second SRS-Ps are the same SRS-P, while the third SRS-P isdifferent. FIG. 11 further depicts an example where the first RIS (RIS1) and the second RIS (2) are Mode 2 RISs (e.g., with a non-negligiblegroup delay above some threshold).

Referring to FIG. 11 , at t₁, the UE transmits an SRS-P 1102, which isreceived by RIS 1 at t₃, and then reflected after a Rx-Tx delay at t₅ asSRS-P reflection 1108, and SRS-P reflection 1108 arrives at the wirelessnode and is measured at TOA₃. At t₁, the UE further transmits an SRS-P1104 along path 1 to the wireless node (denoted as 11041), and alongpath 2 to RIS 1 (denoted as 1104_2). SRS-P 1104_1 arrives at thewireless node and is measured at TOA₁. SRS-P 1104_2 is received by RIS 1at t₄, and then processed (e.g., amplified) with a Rx-Tx delay and thenreflected at t₆ as SRS-P reflection 1106, and SRS-P reflection 1106arrives at the wireless node and is measured at TOA₂. In some designs,the respective TOAs may be processed as RSTDs and sent in a measurementreport to a position estimation entity. However, the raw TOA data mayalternatively be transmitted to the position estimation entity in otherdesigns. In some designs, an offset between t₁ and t₂ is known to thewireless node, and may either be used to adjust the raw TOAs and/or theprocessed measurements (e.g., RSTDs). Hence, in FIG. 11 , the first,second and third SRS-Ps include two or more different SRS-Ps inassociation with one or more known transmission time offsets.

Referring to FIGS. 8-9 , in some designs, the first SRS-P typecorresponds to a default SRS-P type, and the second SRS-P typecorresponds to a RIS-specific SRS-P type. For example, the first SRS-Ptype corresponds to a default SRS-P type (e.g., legacy SRS-P, as a UEwould transmit to gNB in current systems), and the second SRS-P typecorresponds to a RIS-specific SRS-P type (e.g., associated with narroweror more focused beams that are RIS-specific, based on a differentpathloss reference for power control, etc.).

Referring to FIGS. 8-9 , in some designs, the measurement informationmay include the first, second and third TOAs (e.g., raw TOA data), orone or more time difference of arrival (TDOA) measurements based on thefirst, second and third TOAs, or one or more reference signal timedifferences (RSTDs) based on the one or more TDOA measurements, or acombination thereof. In an example, the wireless node (e.g., servinggNB) computes and reports the RSTD (RSTD_1) between serving gNB and theRIS 1 with equation (below equation give an example for RIS 1, but itcan be generalized for other RIS) with respect to FIG. 10 (e.g., forsimplicity so transmission offsets and Rx-Tx delay can be ignored):

RSTD_1=TOA₁ −t ₂=TOA₁−(TOA₂ −T _(prop, RIS 1→wireless_node))

where T_(prop, RIS 1→wireless_node) corresponds to the propagation timealong path 1004. Here, T_(prop, RIS 1→wireless_node) can either bemeasured or computed, as noted above, because the RIS 1 location may beknown (along with the wireless node location). In other designs, if theSRS resources are two different SRS transmitted at different times as inFIG. 11 , the RSTD report could compensate this time offset or thelocation server will compensate the time offset in the UE positioningcalculation.

Referring to FIGS. 8-9 , in some designs, a first propagation time(e.g., T_(prop, RIS 1→wireless_node)) between the wireless node and thefirst RIS is known, a second propagation time (e.g.,T_(prop, RIS 2→wireless_node)) between the wireless node and the secondRIS is known, and the measurement information is based on the first andsecond known propagation times. In some designs, the measurementinformation is computed based on the first and second known propagationtimes, or the measurement information is configured to be furtherprocessed by the first and second known propagation times at theposition estimation entity. In some designs, the first and secondpropagation times are estimated via a radio access technology (RAT)positioning scheme, or the first and second propagation times areestimated via a RAT-independent positioning scheme (e.g., high-precisionPRS or other hybrid positioning methodology). In some designs, thewireless node may report “TOA₁−t₂” to reduce the report overhead (e.g.,because T_(prop, RIS 2→wireless_node) may be known at the positionestimation entity). In some designs, the processes of 800-900 may bebased on measurements of signals between a single wireless node (e.g.,serving gNB) and multiple RIS (e.g., suitable for the low tier UEpositioning of RedCap UEs, since neighboring cell measurement is notrequired). However, in other designs, the processes of 800-900 of FIGS.8-9 could be expanded to scenarios with multiple wireless nodes (e.g.,gNBs) performing the TOA measurements. In some designs, since there isno tight synchronization requirement for the processes of 800-900 ofFIGS. 8-9 , RIS aided UL-TDOA positioning accuracy may potentially besuperior to that of the legacy Rel-16 UL TDOA technique.

Referring to FIGS. 8-9 , in some designs, the wireless node maycorrespond to a serving base station of the UE, or the wireless nodecorresponds to a non-serving base station of the UE, or the wirelessnode corresponds to another UE associated with a known location.

Referring to FIGS. 8-9 , in some designs, the UE may correspond to areduced capability (RedCap) UE or a non-RedCap UE.

Referring to FIGS. 8-9 , in some designs, the position estimation entitymay correspond to the wireless node, and the transmission of themeasurement information corresponds to a transfer of the measurementinformation from one logical component of the wireless node to anotherlogical component of the wireless node.

Referring to FIGS. 8-9 , in some designs, the position estimation entitymay correspond to the UE, a serving base station of the UE, a locationmanagement function (LMF), a location server, or a combination thereof.

Referring to FIGS. 8-9 , in some designs, the first and second RISsinclude at least one RIS of a first type (e.g., Mode 1 RIS) that isconfigured to reflect reference signals without baseband processing, orthe first and second RISs comprise at least one RIS of a second type(e.g., Mode 2 RIS) that is configured to reflect reference signals withlimited baseband processing in association with a predetermined timinggroup delay or a dynamically reported timing group delay, or acombination thereof. In another aspect, the group delay is predeterminedor pre-measured by another device (e.g., a calibrated RIS). In thisoption, the RIS need not have any baseband processing capability.

In the detailed description above it can be seen that different featuresare grouped together in examples. This manner of disclosure should notbe understood as an intention that the example clauses have morefeatures than are explicitly mentioned in each clause. Rather, thevarious aspects of the disclosure may include fewer than all features ofan individual example clause disclosed. Therefore, the following clausesshould hereby be deemed to be incorporated in the description, whereineach clause by itself can stand as a separate example. Although eachdependent clause can refer in the clauses to a specific combination withone of the other clauses, the aspect(s) of that dependent clause are notlimited to the specific combination. It will be appreciated that otherexample clauses can also include a combination of the dependent clauseaspect(s) with the subject matter of any other dependent clause orindependent clause or a combination of any feature with other dependentand independent clauses. The various aspects disclosed herein expresslyinclude these combinations, unless it is explicitly expressed or can bereadily inferred that a specific combination is not intended (e.g.,contradictory aspects, such as defining an element as both an insulatorand a conductor). Furthermore, it is also intended that aspects of aclause can be included in any other independent clause, even if theclause is not directly dependent on the independent clause.

Implementation examples are described in the following numbered clauses:

Clause 1. A method of operating a wireless node, comprising: measuring afirst time of arrival (TOA) of a first sounding reference signal forpositioning (SRS-P) from a user equipment (UE); measuring a second TOAof a reflection of a second SRS-P from the UE off of a firstreconfigurable intelligent surface (RIS); measuring a third TOA of areflection of a third SRS-P from the UE off of a second RIS; andtransmitting, to a position estimation entity, measurement informationbased on the first, second and third TOAs.

Clause 2. The method of clause 1, wherein the first, second and thirdSRS-Ps correspond to the same SRS-P.

Clause 3. The method of any of clauses 1 to 2, wherein the first, secondand third SRS-Ps comprise two or more different SRS-Ps in associationwith one or more known transmission time offsets.

Clause 4. The method of any of clauses 1 to 3, wherein the first SRS-Pis associated with a first SRS-P type and the second and third SRS-Psare associated with a second SRS-P type.

Clause 5. The method of clause 4, wherein the first SRS-P typecorresponds to a default SRS-P type, and wherein the second SRS-P typecorresponds to a RIS-specific SRS-P type.

Clause 6. The method of any of clauses 1 to 5, wherein the measurementinformation comprises: the first, second and third TOAs, or one or moretime difference of arrival (TDOA) measurements based on the first,second and third TOAs, or one or more reference signal time differences(RSTDs) based on the one or more TDOA measurements, or a combinationthereof.

Clause 7. The method of any of clauses 1 to 6, wherein the wireless nodecorresponds to a serving base station of the UE, or wherein the wirelessnode corresponds to a non-serving base station of the UE, or wherein thewireless node corresponds to another UE associated with a knownlocation.

Clause 8. The method of any of clauses 1 to 7, wherein the UEcorresponds to a reduced capability (RedCap) UE or a non-RedCap UE.

Clause 9. The method of any of clauses 1 to 8, wherein the positionestimation entity corresponds to the wireless node, and wherein thetransmission of the measurement information corresponds to a transfer ofthe measurement information from one logical component of the wirelessnode to another logical component of the wireless node.

Clause 10. The method of any of clauses 1 to 9, wherein the positionestimation entity corresponds to the UE, a serving base station of theUE, a location management function (LMF), a location server, or acombination thereof.

Clause 11. The method of any of clauses 1 to 10, wherein a firstpropagation time between the wireless node and the first RIS is known,wherein a second propagation time between the wireless node and thesecond RIS is known, and wherein the measurement information is based onthe first and second known propagation times.

Clause 12. The method of clause 11, wherein the measurement informationis computed based on the first and second known propagation times, orwherein the measurement information is configured to be furtherprocessed by the first and second known propagation times at theposition estimation entity.

Clause 13. The method of clause 12, wherein the first and secondpropagation times are estimated via a radio access technology (RAT)positioning scheme, or wherein the first and second propagation timesare estimated via a RAT-independent positioning scheme.

Clause 14. The method of any of clauses 1 to 13, wherein the first andsecond RISs comprise at least one RIS of a first type that is configuredto reflect reference signals without baseband processing, or wherein thefirst and second RISs comprise at least one RIS of a second type that isconfigured to reflect reference signals with baseband processing inassociation with a predetermined timing group delay or a dynamicallyreported timing group delay, or a combination thereof.

Clause 15. A method of operating a position estimation entity,comprising: receiving, from a wireless node, measurement informationbased on a first time of arrival (TOA) of a first sounding referencesignal for positioning (SRS-P) from a user equipment (UE), a second TOAof a reflection of a second SRS-P from the UE off of a firstreconfigurable intelligent surface (RIS), and a third TOA of areflection of a third SRS-P from the UE off of a second RIS; anddetermining a positioning estimate of the UE based at least in part onthe measurement information.

Clause 16. The method of clause 15, wherein the first, second and thirdSRS-Ps correspond to the same SRS-P.

Clause 17. The method of clause 16, wherein the first, second and thirdSRS-Ps comprise two or more different SRS-Ps in association with one ormore known transmission time offsets.

Clause 18. The method of any of clauses 16 to 17, wherein the firstSRS-P is associated with a first SRS-P type and the second and thirdSRS-Ps are associated with a second SRS-P type.

Clause 19. The method of any of clauses 19 to 18, wherein the firstSRS-P type corresponds to a default SRS-P type, and wherein the secondSRS-P type corresponds to a RIS-specific SRS-P type.

Clause 20. The method of any of clauses 16 to 19, wherein themeasurement information comprises: the first, second and third TOAs, orone or more time difference of arrival (TDOA) measurements based on thefirst, second and third TOAs, or one or more reference signal timedifferences (RSTDs) based on the one or more TDOA measurements, or acombination thereof.

Clause 21. The method of any of clauses 16 to 20, wherein the wirelessnode corresponds to a serving base station of the UE, or wherein thewireless node corresponds to a non-serving base station of the UE, orwherein the wireless node corresponds to another UE associated with aknown location.

Clause 22. The method of any of clauses 16 to 21, wherein the UEcorresponds to a reduced capability (RedCap) UE.

Clause 23. The method of any of clauses 16 to 22, wherein the positionestimation entity corresponds to the wireless node, and wherein thereception of the measurement information corresponds to a transfer ofthe measurement information from one logical component of the wirelessnode to another logical component of the wireless node.

Clause 24. The method of any of clauses 16 to 23, wherein the positionestimation entity corresponds to the UE, a serving base station of theUE, a location management function (LMF), a location server, or acombination thereof.

Clause 25. The method of any of clauses 16 to 24, wherein a firstpropagation time between the wireless node and the first RIS is known,wherein a second propagation time between the wireless node and thesecond RIS is known, and wherein the measurement information is based onthe first and second known propagation times.

Clause 26. The method of clause 25, wherein the measurement informationis computed based on the first and second known propagation times, orwherein the measurement information is configured to be furtherprocessed by the first and second known propagation times at theposition estimation entity.

Clause 27. The method of clause 26, wherein the first and secondpropagation times are estimated via a radio access technology (RAT)positioning scheme, or wherein the first and second propagation timesare estimated via a RAT-independent positioning scheme.

Clause 28. The method of any of clauses 16 to 27, wherein the first andsecond RISs comprise at least one RIS of a first type that is configuredto reflect reference signals without baseband processing, or wherein thefirst and second RISs comprise at least one RIS of a second type that isconfigured to reflect reference signals with baseband processing inassociation with a predetermined timing group delay or a dynamicallyreported timing group delay, or a combination thereof.

Clause 29. An apparatus comprising a memory and at least one processorcommunicatively coupled to the memory, the memory and the at least oneprocessor configured to perform a method according to any of clauses 1to 28.

Clause 30. An apparatus comprising means for performing a methodaccording to any of clauses 1 to 28.

Clause 31. A non-transitory computer-readable medium storingcomputer-executable instructions, the computer-executable comprising atleast one instruction for causing a computer or processor to perform amethod according to any of clauses 1 to 28.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the aspects disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an ASIC, a field-programmable gate array (FPGA), or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,for example, a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The methods, sequences and/or algorithms described in connection withthe aspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in random access memory (RAM), flashmemory, read-only memory (ROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An example storage medium is coupled to the processor such thatthe processor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal (e.g., UE). In thealternative, the processor and the storage medium may reside as discretecomponents in a user terminal.

In one or more example aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects of thedisclosure, it should be noted that various changes and modificationscould be made herein without departing from the scope of the disclosureas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the aspects of the disclosuredescribed herein need not be performed in any particular order.Furthermore, although elements of the disclosure may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

What is claimed is:
 1. A method of operating a wireless node,comprising: measuring a first time of arrival (TOA) of a first soundingreference signal for positioning (SRS-P) from a user equipment (UE);measuring a second TOA of a reflection of a second SRS-P from the UE offof a first reconfigurable intelligent surface (RIS); measuring a thirdTOA of a reflection of a third SRS-P from the UE off of a second RIS;and transmitting, to a position estimation entity, measurementinformation based on the first, second and third TOAs.
 2. The method ofclaim 1, wherein the first, second and third SRS-Ps correspond to thesame SRS-P.
 3. The method of claim 1, wherein the first, second andthird SRS-Ps comprise two or more different SRS-Ps in association withone or more known transmission time offsets.
 4. The method of claim 1,wherein the first SRS-P is associated with a first SRS-P type and thesecond and third SRS-Ps are associated with a second SRS-P type.
 5. Themethod of claim 4, wherein the first SRS-P type corresponds to a defaultSRS-P type, and wherein the second SRS-P type corresponds to aRIS-specific SRS-P type.
 6. The method of claim 1, wherein themeasurement information comprises: the first, second and third TOAs, orone or more time difference of arrival (TDOA) measurements based on thefirst, second and third TOAs, or one or more reference signal timedifferences (RSTDs) based on the one or more TDOA measurements, or acombination thereof.
 7. The method of claim 1, wherein the wireless nodecorresponds to a serving base station of the UE, or wherein the wirelessnode corresponds to a non-serving base station of the UE, or wherein thewireless node corresponds to another UE associated with a knownlocation.
 8. The method of claim 1, wherein the UE corresponds to areduced capability (RedCap) UE or a non-RedCap UE.
 9. The method ofclaim 1, wherein the position estimation entity corresponds to thewireless node, and wherein the transmission of the measurementinformation corresponds to a transfer of the measurement informationfrom one logical component of the wireless node to another logicalcomponent of the wireless node.
 10. The method of claim 1, wherein theposition estimation entity corresponds to the UE, a serving base stationof the UE, a location management function (LMF), a location server, or acombination thereof.
 11. The method of claim 1, wherein a firstpropagation time between the wireless node and the first RIS is known,wherein a second propagation time between the wireless node and thesecond RIS is known, and wherein the measurement information is based onthe first and second known propagation times.
 12. The method of claim11, wherein the measurement information is computed based on the firstand second known propagation times, or wherein the measurementinformation is configured to be further processed by the first andsecond known propagation times at the position estimation entity. 13.The method of claim 12, wherein the first and second propagation timesare estimated via a radio access technology (RAT) positioning scheme, orwherein the first and second propagation times are estimated via aRAT-independent positioning scheme.
 14. The method of claim 1, whereinthe first and second RISs comprise at least one RIS of a first type thatis configured to reflect reference signals without baseband processing,or wherein the first and second RISs comprise at least one RIS of asecond type that is configured to reflect reference signals withbaseband processing in association with a predetermined timing groupdelay or a dynamically reported timing group delay, or a combinationthereof.
 15. A method of operating a position estimation entity,comprising: receiving, from a wireless node, measurement informationbased on a first time of arrival (TOA) of a first sounding referencesignal for positioning (SRS-P) from a user equipment (UE), a second TOAof a reflection of a second SRS-P from the UE off of a firstreconfigurable intelligent surface (RIS), and a third TOA of areflection of a third SRS-P from the UE off of a second RIS; anddetermining a positioning estimate of the UE based at least in part onthe measurement information.
 16. The method of claim 15, wherein thefirst, second and third SRS-Ps correspond to the same SRS-P.
 17. Themethod of claim 16, wherein the first, second and third SRS-Ps comprisetwo or more different SRS-Ps in association with one or more knowntransmission time offsets.
 18. The method of claim 16, wherein the firstSRS-P is associated with a first SRS-P type and the second and thirdSRS-Ps are associated with a second SRS-P type.
 19. The method of claim18, wherein the first SRS-P type corresponds to a default SRS-P type,and wherein the second SRS-P type corresponds to a RIS-specific SRS-Ptype.
 20. The method of claim 16, wherein the measurement informationcomprises: the first, second and third TOAs, or one or more timedifference of arrival (TDOA) measurements based on the first, second andthird TOAs, or one or more reference signal time differences (RSTDs)based on the one or more TDOA measurements, or a combination thereof.21. The method of claim 16, wherein the wireless node corresponds to aserving base station of the UE, or wherein the wireless node correspondsto a non-serving base station of the UE, or wherein the wireless nodecorresponds to another UE associated with a known location.
 22. Themethod of claim 16, wherein the UE corresponds to a reduced capability(RedCap) UE.
 23. The method of claim 16, wherein the position estimationentity corresponds to the wireless node, and wherein the reception ofthe measurement information corresponds to a transfer of the measurementinformation from one logical component of the wireless node to anotherlogical component of the wireless node.
 24. The method of claim 16,wherein the position estimation entity corresponds to the UE, a servingbase station of the UE, a location management function (LMF), a locationserver, or a combination thereof.
 25. The method of claim 16, wherein afirst propagation time between the wireless node and the first RIS isknown, wherein a second propagation time between the wireless node andthe second RIS is known, and wherein the measurement information isbased on the first and second known propagation times.
 26. The method ofclaim 25, wherein the measurement information is computed based on thefirst and second known propagation times, or wherein the measurementinformation is configured to be further processed by the first andsecond known propagation times at the position estimation entity. 27.The method of claim 26, wherein the first and second propagation timesare estimated via a radio access technology (RAT) positioning scheme, orwherein the first and second propagation times are estimated via aRAT-independent positioning scheme.
 28. The method of claim 16, whereinthe first and second RISs comprise at least one RIS of a first type thatis configured to reflect reference signals without baseband processing,or wherein the first and second RISs comprise at least one RIS of asecond type that is configured to reflect reference signals withbaseband processing in association with a predetermined timing groupdelay or a dynamically reported timing group delay, or a combinationthereof.
 29. A wireless node, comprising: a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: measure a first time of arrival (TOA) of a first soundingreference signal for positioning (SRS-P) from a user equipment (UE);measure a second TOA of a reflection of a second SRS-P from the UE offof a first reconfigurable intelligent surface (RIS); measure a third TOAof a reflection of a third SRS-P from the UE off of a second RIS; andtransmit, to a position estimation entity, measurement information basedon the first, second and third TOAs.
 30. A position estimation entity,comprising: a memory; at least one transceiver; and at least oneprocessor communicatively coupled to the memory and the at least onetransceiver, the at least one processor configured to: receive, from awireless node, measurement information based on a first time of arrival(TOA) of a first sounding reference signal for positioning (SRS-P) froma user equipment (UE), a second TOA of a reflection of a second SRS-Pfrom the UE off of a first reconfigurable intelligent surface (RIS), anda third TOA of a reflection of a third SRS-P from the UE off of a secondRIS; and determine a positioning estimate of the UE based at least inpart on the measurement information.